[Federal Register Volume 70, Number 67 (Friday, April 8, 2005)]
[Rules and Regulations]
[Pages 18136-18191]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6741]



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Part III





Department of Transportation





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National Highway and Traffic Safety Administration



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49 CFR Parts 571 and 585



Federal Motor Vehicle Safety Standards; Tire Pressure Monitoring 
Systems; Controls and Displays; Final Rule

  Federal Register / Vol. 70, No. 67 / Friday, April 8, 2005 / Rules 
and Regulations  

[[Page 18136]]


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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571 and 585

[Docket No. NHTSA 2005-20586]
RIN 2127-AJ23


Federal Motor Vehicle Safety Standards; Tire Pressure Monitoring 
Systems; Controls and Displays

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule establishes a new Federal motor vehicle safety 
standard (FMVSS) requiring installation of a tire pressure monitoring 
system (TPMS) capable of detecting when one or more of a vehicle's 
tires is significantly under-inflated. This final rule responds to a 
mandate in the Transportation Recall Enhancement, Accountability, and 
Documentation (TREAD) Act. This final rule requires installation in all 
new light vehicles of a TPMS capable of detecting when one or more of 
the vehicle's tires, up to all four tires, is 25 percent or more below 
the manufacturer's recommended inflation pressure (placard pressure) or 
a minimum activation pressure specified in the standard, whichever is 
higher.

DATES: Effective Date: This final rule is effective April 8, 2005, 
except for subpart G of 49 CFR part 585, which is effective September 
1, 2005.
    Compliance Date: Consistent with the phase-in commencing October 5, 
2005, all new light vehicles must be equipped with a TPMS that meets 
the requirements of the standard by September 1, 2007, with the 
following exceptions. Vehicle manufacturers need not meet the 
standard's requirements for the TPMS malfunction indicator and related 
owner's manual language until September 1, 2007 (i.e., at the end of 
the phase-in), and vehicles produced by final-stage manufacturers and 
alterers must be equipped with a compliant TPMS (including a 
malfunction indicator) by September 1, 2008. However, manufacturers may 
voluntarily certify vehicles to FMVSS No. 138 and earn carry-forward 
credits for compliant vehicles, produced in excess of the phase-in 
requirements, that are manufactured between April 8, 2005, and the 
conclusion of the phase-in.
    Petitions for Reconsideration: If you wish to submit a petition for 
reconsideration of this rule, your petition must be received by May 23, 
2005.

ADDRESSES: Petitions for reconsideration should refer to the docket 
number above and be submitted to: Administrator, Room 5220, National 
Highway Traffic Safety Administration, 400 Seventh Street, SW., 
Washington, DC 20590.
    See the SUPPLEMENTARY INFORMATION portion of this document (Section 
VIII; Rulemaking Analyses and Notice) for DOT's Privacy Act Statement 
regarding documents submitted to the agency's dockets.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may call Mr. 
George Soodoo or Mr. Samuel Daniel, Office of Crash Avoidance Standards 
(Telephone: 202-366-2720) (Fax: 202-366-4329).
    For legal issues, you may call Mr. Eric Stas, Office of the Chief 
Counsel (Telephone: 202-366-2992) (Fax: 202-366-3820).
    You may send mail to these officials at National Highway Traffic 
Safety Administration, 400 Seventh Street, SW., Washington, DC 20590.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Executive Summary
    A. Requirements of the Final Rule
    B. Lead Time and Phase-In
    C. Differences Between the Final Rule and the Notice of Proposed 
Rulemaking
    D. Impacts of the Final Rule
II. Background
    A. The TREAD Act
    B. Rulemaking History Prior to the September 2004 Notice of 
Proposed Rulemaking
III. September 2004 Notice of Proposed Rulemaking (NPRM) and Public 
Comments
    A. The NPRM
    B. Summary of Public Comments on the NPRM
IV. The Final Rule and Response to Public Comments
    A. Summary of the Requirements
    B. Lead Time and Phase-In
    C. Response to Public Comments by Issue
    1. Low Tire Pressure Warning Lamp Activation Requirement
    (a) Under-Inflation Detection Level
    (b) Time Period for Low Pressure Detection
    2. TPMS Malfunction Indicator Lamp (MIL) Activation Requirements
    (a) Time Period for Malfunction Detection
    (b) What Constitutes a TPMS Malfunction?
    (c) MIL Disablement
    3. Telltale Requirements
    (a) Function and Format of the Combined Low Pressure Warning/
Malfunction Indicator Lamp
    (b) Telltale Symbols for Low Pressure Warning and Malfunction 
Indication
    (c) Telltale Color
    (i) Low Pressure Warning Telltale
    (ii) Malfunction Indicator Telltale
    (d) Telltale Extinguishment Requirements
    (e) Telltale Illumination Priority
    (f) Supplemental Telltale
    4. Tire-Related Issues
    (a) Replacement Tires and Spare Tires
    (b) Tire Reserve Load
    (c) Changes to Tire Publications
    (d) Minimum Activation Pressure
    5. Owner's Manual Requirements
    6. Test Procedures
    (a) Calibration Time
    (b) Driving Conditions
    (c) MIL Activation
    (d) Vehicle Cool-Down Period
    (e) Testing with Pressures Other Than Placard Pressure
    (f) System Reset
    7. Lead Time and Phase-In
    (a) Lead Time
    (b) Phase-In Schedule
    8. Small Business Impacts
    9. Environmental Impacts
    10. Maintenance Issues
    (a) TPMS Maintenance
    (b) Tire Maintenance
    11. Markings for Vehicles with Direct TPMSs
    12. Definitions
    (a) ``Tires''
    (b) ``Manual Reset''
    13. Educational Efforts
    14. Alternative Systems
    15. Over-Inflation Detection
    16. Temperature and Altitude Compensation
    17. System Longevity
    18. Harmonization
V. Benefits
VI. Costs
VII. Regulatory Alternatives
VIII. Rulemaking Analyses and Notices

I. Executive Summary

    This final rule re-establishes FMVSS No. 138, Tire Pressure 
Monitoring Systems, which requires installation of a tire pressure 
monitoring system in light vehicles, thereby implementing a mandate in 
the TREAD Act. In accord with the Act, the objective of this standard 
is to supplement regular tire maintenance on the part of drivers by 
providing a warning system to alert them when one or more of a 
vehicle's tires become significantly under-inflated. Under-inflation of 
tires increases the likelihood of many different types of crashes, 
including those involving: (1) Skidding and/or

[[Page 18137]]

loss of control of the vehicle; (2) hydroplaning; (3) increases in 
stopping distance; (4) flat tires and blowouts, and (5) overloading of 
the vehicle. We anticipate that 90 percent of drivers will respond to a 
TPMS low tire pressure warning by re-inflating their tires to the 
recommended placard pressure. Once all new light vehicles are equipped 
with compliant TPMSs, we expect that a resulting 119-121 fatalities 
would be prevented each year.
    As background, we note that Standard No. 138 was promulgated 
previously through a final rule published in the Federal Register on 
June 5, 2002 (67 FR 38704). It included two compliance options (i.e., a 
TPMS with a four-tire, 25-percent under-inflation detection capability 
or a TPMS with a one-tire, 30-percent under-inflation detection 
capability). However, on August 6, 2003, the U.S. Court of Appeals for 
the Second Circuit (Second Circuit) issued its opinion in Public 
Citizen v. Mineta,\1\ which held that the TREAD Act requires a TPMS 
capable of detecting when any combination of tires, up to all four 
tires, is significantly under-inflated. It vacated FMVSS No. 138 and 
directed the agency to conduct further rulemaking. This final rule sets 
requirements for the TPMS standard in a manner consistent with the 
Second Circuit's opinion. It also responds to numerous public comments 
submitted in response to the agency's September 16, 2004 notice of 
proposed rulemaking (NPRM) (69 FR 55896).
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    \1\ 340 F.3d 39 (2d Cir. 2003).
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A. Requirements of the Final Rule

    After careful consideration of all available information, including 
public comments, the agency has decided to retain in the final rule 
most of the elements of the proposed rule, with the primary changes 
involving the detection times for providing the low tire pressure 
warning and TPMS malfunction warning, modification of the minimum 
activation pressure values for certain light truck tires, and 
modifications to the standard's phase-in schedule. Although public 
comments on the NPRM discussed a wide variety of issues, the majority 
of comments focused on the topics of the TPMS malfunction indicator and 
the proposed schedule for lead time and phase-in, the two major aspects 
of the NPRM not raised at earlier stages of the TPMS rulemaking.
    As reflected in the final rule, FMVSS No. 138 is a performance 
standard. The agency has sought to establish the standard in a fashion 
that both meets the need for motor vehicle safety and is also 
technology-neutral. Particularly in light of the rapid advances in TPMS 
technology in the past few years, we expect that vehicle manufacturers 
will have a number of technologies available for compliance purposes. 
Although the details of the standard, public comments, and the agency's 
response thereto, are discussed at length in the balance of this 
document, the following points summarize the key requirements of the 
standard.
    Consistent with the Second Circuit's opinion, FMVSS No. 138 
requires new passenger cars, multi-purpose passenger vehicles, trucks, 
and buses with a gross vehicle weight rating (GVWR) of 4,536 kg (10,000 
pounds) or less, except those with dual wheels on an axle, to be 
equipped with a TPMS to alert the driver when one or more of the 
vehicle's tires, up to a total of all four tires, is significantly 
under-inflated. Specifically, the TPMS must warn the driver when the 
pressure in one or more of the vehicle's tires is 25 percent or more 
below the vehicle manufacturer's recommended cold inflation pressure, 
or a minimum level of pressure specified in the standard, whichever 
pressure is higher. (We note that in response to a petition for 
rulemaking by the Alliance of Automobile Manufacturers (Alliance) and 
that organization's subsequent, related comments on the NPRM, we have 
decided, as an interim measure, to modify our minimum activation 
pressure (MAP) values for some light truck tires under the standard. 
Once the agency conducts further safety research, we will either 
confirm or propose to modify these MAP requirements in response to that 
petition.)
    If any tire drops below the standard's activation threshold, the 
TPMS is required to provide the low tire pressure warning by 
illuminating a yellow telltale within 20 minutes of additional travel 
within a speed range of 50-100 km/hr. This telltale must remain 
illuminated (and re-illuminate upon subsequent vehicle start-ups) until 
the under-inflation condition has been corrected. The agency has 
determined that the specified under-inflation threshold and the 
detection time will allow the TPMS to provide a timely warning that 
permits the driver to take corrective action before adverse 
consequences ensue. Thus, we believe that the low inflation pressure 
detection requirement of the standard both fulfills the mandate of the 
TREAD Act and meets the need for motor vehicle safety.
    Because a small number of aftermarket and replacement tires have 
construction characteristics that may prevent the continued proper 
functioning of the TPMS when the original equipment tires are replaced 
and because of the difficulty in identifying those problematic tires, 
NHTSA has decided to require the vehicle to be certified with the tires 
originally installed on the vehicle at the time of initial vehicle 
sale. (This reflects a change from the June 2002 final rule, which 
required vehicle manufacturer to certify continued compliance with any 
optional or replacement tires of the size(s) recommended by the vehicle 
manufacturer.)
    Nevertheless, we expect that a typical vehicle will outlast its 
original set of tires, and we continue to believe that it is important 
that drivers continue to receive the benefits of the TPMS after the 
vehicle's tires are replaced. Therefore, we have decided upon a 
different approach than that contained in the June 2002 final rule for 
addressing the issue of maintaining proper TPMS functionality when a 
vehicle's original tires are replaced. Specifically, the final rule 
requires the TPMS to include a malfunction indicator (provided either 
by a separate telltale or a combined low tire pressure/malfunction 
indicator telltale) that would alert the driver in situations in which 
the TPMS is unable to detect low tire pressure.
    This malfunction indicator is required to detect incompatible 
replacement tires, as well as other system faults. Similar to the low 
tire pressure warning, the system is required to trigger a TPMS 
malfunction warning telltale within 20 minutes of additional travel 
within a speed range of 50-100 km/hr after such a malfunction occurs. 
Consistent with the specific requirements of the standard, this 
telltale must remain illuminated (and re-illuminate upon subsequent 
vehicle start-ups) until the TPMS malfunction has been corrected. We 
believe that the TPMS malfunction indicator will provide useful 
information to the driver regarding the long-term operability of the 
TPMS, thereby increasing the overall benefits of the system.
    The final rule also specifies required language to be included in 
the vehicle owner's manual (or in writing to the first purchaser if 
there is no owner's manual) that describes the purpose of the low tire 
pressure warning telltale, the consequences of significantly under-
inflated tires, the meaning of the low tire pressure telltale when it 
is illuminated, and corrective action to be taken. The owner's manual 
must also explain the presence and operation of the TPMS malfunction 
indicator and the potential problems associated with aftermarket and 
replacement tires and

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rims that may prevent continued TPMS functionality. These provisions 
are designed to ensure that consumers are aware of the importance of 
regular tire maintenance and of the supporting role played by their 
vehicle's TPMS.
    The final rule provides that compliance testing for FMVSS No. 138 
will be conducted on a specific test course, namely the Southern Loop 
of the Treadwear Course in and around San Angelo, Texas. We believe 
that this approach offers several advantages. First, testing can be 
conducted in a timely fashion without the need to design or build a new 
test track. Further, this course has already been used for several 
years by NHTSA and the tire industry for uniform tire quality grading 
(UTQG) purposes. We believe that the specified test course provides an 
objective test that is representative of a variety of roadways and real 
world conditions.

B. Lead Time and Phase-In

    In order to provide the public with the safety benefits of TPMSs as 
rapidly as possible, compliance with this final rule is set to commence 
on October 5, 2005, which marks the start of a two-part phase-in 
period. Subject to the special provisions discussed below, the phase-in 
schedule for FMVSS No. 138 is as follows: 20 percent of a vehicle 
manufacturer's light vehicles are required to comply with the standard 
during the period from October 5, 2005, to August 31, 2006; 70 percent 
during the period from September 1, 2006 to August 31, 2007, and all 
light vehicles thereafter.
    For the reasons discussed in detail in section IV.B of this notice, 
we believe that it is practicable for vehicle manufacturers to meet the 
requirements of the phase-in discussed above, with the following 
exceptions. We have decided to defer vehicle manufacturers' compliance 
with the standard's malfunction indicator requirements and associated 
owner's manual language requirements until September 1, 2007. (There is 
no separate phase-in for the malfunction indicator requirements.) After 
consideration of the many public comments from vehicle manufacturers on 
this issue, we understand that adding the TPMS malfunction indicator 
will involve substantial design and production changes and that 
additional lead time will be required to effect those changes. In 
addition, our analysis demonstrates that the safety benefits associated 
with the early introduction of TPMSs, even without malfunction 
indicators, far outweigh the benefits of delaying the standard until 
all systems also can meet the malfunction indicator requirements. We 
note that manufacturers may voluntarily install a TPMS malfunction 
indicator prior to the mandatory compliance date.
    Because our statute generally requires that a standard may not 
compel compliance less than 180 days after the standard is 
prescribed,\2\ we have decided to postpone the starting compliance date 
from the NPRM's proposed date of September 1, 2005 to a date that 
corresponding to 180 days after publication of this final rule. 
However, we have decided to have the balance of the standard's phase-in 
coincide with traditional model year production schedules, in order to 
mitigate production and cost impacts.
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    \2\ 49 U.S.C. 30111(d).
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    We have decided not to delay the start of compliance until Model 
Year 2007, as several commenters suggested. If the agency were to 
forego the first year of the phase-in, we would expect to lose 24 lives 
and to have 1,675 more injuries than would have occurred if TPMSs had 
been provided in vehicles, as called for in the final rule's phase-in.
    Moreover, vehicle manufacturers have been well aware of the key 
requirements of the final rule (other then the malfunction indicator 
requirement), at least since the time of the Second Circuit's decision 
in August 2003 (if not earlier), and the September 2004 NPRM clearly 
conveyed the agency's intention to begin a phase-in that would coincide 
with Model Year (MY) 2006. Further, they did not provide any data to 
demonstrate that compliance with a Fall 2005 start of the phase-in 
would be impracticable. In addition, we believe that concerns related 
to lead time are either rendered moot or significantly mitigated by the 
final rule's allowance of both carry-forward and carry-backward 
credits.
    As a means of maintaining a mandatory compliance date in Fall 2005, 
we have decided to ease implementation further by permitting carry-
forward and carry-back credits. Vehicle manufacturers can earn carry-
forward credits for compliant vehicles, produced in excess of the 
phase-in requirements, that are manufactured between the effective date 
of this rule and the conclusion of the phase-in.\3\ In order to 
maximize the time available to earn such credits, we are making this 
final rule effective upon publication, although vehicle manufacturers 
have no certification responsibilities until the official start of the 
phase-in.
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    \3\ We note that carry-forward credits may not be used to defer 
the mandatory compliance date of September 1, 2007 for all covered 
vehicles.
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    With carry-backward credits, manufacturers may defer compliance 
with a part or all of the certification requirements under the standard 
for the first period of the phase-in, provided they certify a 
correspondingly increased number of vehicles during the second period 
of the phase-in. We believe that permitting carry-backward credits 
would not impact the overall safety benefits of the final rule because 
the same number of vehicles would be subject to compliance 
certification, although the distribution may vary over the model years 
of the phase-in.
    On other topics related to the phase-in, NHTSA has decided to 
exclude multi-stage manufacturers and alterers from the requirements of 
the phase-in and to extend by one year the time for compliance by those 
manufacturers (i.e., until September 1, 2008). The final rule also 
excludes small volume manufacturers (i.e., manufacturers producing less 
than 5,000 vehicles for sale in the U.S. market in one year) from the 
phase-in, requiring vehicles produced by such manufacturers to comply 
with the standard on September 1, 2007.

C. Differences Between the Final Rule and the Notice of Proposed 
Rulemaking

    As noted above, NHTSA has decided to adopt most of the provisions 
contained in the NPRM as part of this final rule. The main differences 
between the NPRM and the final rule involve the phase-in schedule for 
the standard, the requirements for low tire pressure and TPMS 
malfunction detection time, changes to the minimum activation pressure 
for certain light truck tires, and modifications to the vehicle owner's 
manual requirements. A number of minor technical modifications also 
were incorporated in the final rule in response to public comments on 
the NPRM. All of these changes and their rationale are discussed fully 
in the balance of this document. However, the following points briefly 
describe the main differences between the NPRM and this final rule.
     In the final rule, we have decided to increase the time 
period for the TPMS to detect low tire pressure to 20 minutes. The NPRM 
had proposed a time period of 10 minutes for the TPMS to detect low 
tire pressure and illuminate the warning telltale.
     The final rule specifies a time period for the TPMS to 
detect a system malfunction and to illuminate the TPMS malfunction 
indicator (20 minutes) and acknowledged that many systems may require 
vehicle motion to detect a malfunction. The NPRM had been silent on 
these matters.

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     The agency has decided to require the words (`` TPMS'') 
for the dedicated TPMS malfunction telltale, rather than the symbol 
proposed in the NPRM. We have also lengthened the time period for 
flashing of the combined low tire pressure/malfunction indicator 
telltale from the proposed one minute to a period of 60-90 seconds.
     The final rule has adopted minimum activation pressures 
for light truck Load Range ``D'' and ``E'' tires of 35 psi (240 kPa), 
which is different from the values in the NPRM. (However, the agency 
has stated that it is conducting further research in this area and that 
it may revisit this issue.)
     The final rule's requirements for the specified statement 
in the owner's manual regarding the TPMS have changed from the NPRM. 
Specifically, these changes include clarification that both aftermarket 
tires and rims may affect the TPMS's continued functionality, tailoring 
of the language to reflect the two options for the TPMS malfunction 
indicator, stressing of the driver's ongoing responsibility for regular 
tire maintenance, and alerting consumers that some replacement tires 
may call for an inflation pressure different than what is reflected on 
the vehicle placard.
     In the final rule's test procedures, we have deleted the 
NPRM's test requirements related to system reset. We have decided that 
this provision is impracticable, based upon how most resets operate, 
and unnecessary, because vehicles equipped with a TPMS reset normally 
include instructions for the proper use of the reset feature as part of 
the owner's manual.
    The final rule's phase-in schedule has changed from the NPRM's 50-
90-100% requirement to a 20-70-100% requirement. In another change from 
the NPRM, vehicle manufacturers are not required to meet the standard's 
requirements for the TPMS malfunction indicator (and associated owner's 
manual requirements) until the end of the phase-in (i.e., September 1, 
2007).
     The final rule permits vehicle manufacturers to elect to 
use carry-backward credits in meeting the phase-in requirements under 
the standard. That provision was not present in the NPRM.
     The final rule extends the compliance date for final-stage 
manufacturers and alterers by one year (i.e., to September 1, 2008). 
The NPRM had proposed to require compliance for these manufacturers' 
production by September 1, 2007.

D. Impacts of the Final Rule

    Depending upon the technology chosen for compliance, the agency 
estimates that the total quantified safety benefits from reductions in 
crashes due to skidding/loss of control, stopping distance, flat tires, 
and blowouts, will be 119-121 fatalities prevented and 8,373-8,568 
injuries prevented or reduced in severity each year, once all light 
vehicles meet the TPMS requirement.
    Additional benefits are expected to accrue from the final rule as a 
result of improved fuel economy ($19.07-$23.08 per vehicle over its 
lifetime), longer tread life ($3.42-$4.24 per vehicle), and property 
damage savings and travel delay savings from avoided crashes ($7.70-
$7.79 per vehicle) (assuming a three-percent discount rate).
    The agency estimates that the average cost per vehicle to meet the 
standard's requirements to be $48.44-$69.89, depending upon the 
technology chosen for compliance. Since approximately 17 million light 
vehicles are produced for sale in the U.S. each year, the total annual 
vehicle cost is expected to range from approximately $823-$1,188 
million per year.

II. Background

A. The TREAD Act

    Congress enacted the TREAD Act \4\ on November 1, 2000. Section 13 
of that Act \5\ required the Secretary of Transportation, within one 
year of the statute's enactment, to complete a rulemaking ``to require 
a warning system in new motor vehicles to indicate to the operator when 
a tire is significantly under inflated.'' Section 13 also required the 
regulation to take effect within two years of the completion of the 
rulemaking. Responsibility for this rulemaking was delegated to NHTSA.
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    \4\ Pub. L. 106-414, 114 Stat. 1800 (2000).
    \5\ See 49 U.S.C. 30123 note (2003).
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B. Rulemaking History Prior to the September 2004 Notice of Proposed 
Rulemaking

    FMVSS No. 138, Tire Pressure Monitoring Systems, has had a 
protracted regulatory history. The following discussion briefly 
summarizes the key milestones in the TPMS rulemaking process.
    Today's final rule was preceded by an initial NPRM on July 26, 2001 
(66 FR 38982). After considering public comments received on that NPRM, 
NHTSA prepared a final rule, which was submitted to the Office of 
Management and Budget (OMB) for review. After reviewing the draft final 
rule, OMB returned it to NHTSA for further consideration, with a letter 
explaining the reasons for doing so, on February 12, 2002.
    On June 5, 2002, NHTSA published a final rule for TPMS (67 FR 
38704). Consistent with the OMB return letter, the agency divided the 
TPMS final rule into two parts, because it decided to defer its 
decision as to which long-term performance requirements for TPMS would 
best satisfy the mandate of the TREAD Act. This deferral was intended 
to allow the agency time to consider additional data on the effect and 
performance of TPMSs currently in use.
    The June 5, 2002 final rule provided two compliance options during 
the interim period (i.e., between November 1, 2003 and October 31, 
2006). Under the first compliance option, vehicle manufacturers would 
have been required to equip their light vehicles (i.e., those with a 
GVWR of 4,536 kg (10,000 pounds) or less) with TPMSs to warn the driver 
when the pressure in any single tire or in each tire in any combination 
of tires, up to a total of four tires, is 25 percent or more below the 
vehicle manufacturer's recommended cold inflation pressure for the 
tires, or a minimum level of pressure specified in the standard, 
whichever pressure is higher. Under the second compliance option, the 
vehicle's TPMS would have been required to warn the driver when the 
pressure in any single tire is 30 percent or more below the vehicle 
manufacturer's recommended cold inflation pressure for the tires, or a 
minimum level of pressure specified in the standard, whichever pressure 
is higher.\6\
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    \6\ The minimum levels of pressure were the same for both 
compliance options.
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    The two compliance options were outgrowths of the alternative sets 
of requirements proposed in the initial NPRM. In response to comments 
indicating that current indirect TPMSs could not meet the NPRM's 
proposed detection requirements, the agency adopted a one-tire, 30-
percent option that would have permitted indirect TPMSs to be used 
during the phase-in period.\7\ NHTSA received 13 petitions

[[Page 18140]]

for reconsideration of the June 2002 final rule, raising a variety of 
issues.
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    \7\ There are two types of TPMSs currently available, direct 
TPMSs and indirect TPMSs. Direct TPMSs have a pressure sensor in 
each wheel that transmits pressure information to a receiver. In 
contrast, indirect TPMSs do not have tire pressure sensors, but 
instead rely on the wheel speed sensors, typically a component of an 
anti-lock braking system, to detect and compare differences in the 
rotational speed of a vehicle's wheels, which correlate to 
differences in tire pressure.
    We anticipate that new types of TPMS technology may be developed 
in the future that will be capable of meeting the standard's 
requirements. For example, such systems might incorporate aspects of 
both direct and indirect TPMSs (i.e., hybrid systems). In concert 
with TPMS suppliers, tire manufacturers might be able to incorporate 
TPMS sensors directly into the tires themselves. In issuing a 
performance standard, NHTSA is cognizant of and seeks to encourage 
technological innovation.
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    However, after issuance of the June 2002 final rule, Public 
Citizen, Inc., New York Public Interest Research Group, and the Center 
for Auto Safety filed a suit challenging certain aspects of the TPMS 
regulation. The Court of Appeals for the Second Circuit issued its 
opinion in Public Citizen, Inc. v. Mineta on August 6, 2003, which held 
that the agency's adoption in the standard of a one-tire, 30-percent 
compliance option was ``contrary to the intent of the TREAD Act and, in 
light of the relative shortcomings of indirect systems, arbitrary and 
capricious.'' \8\ The Court found that the TREAD Act unambiguously 
mandates TPMSs capable of monitoring each tire, up to a total of four 
tires, effectively precluding the one-tire, 30-percent option, or any 
similar option that cannot detect under-inflation in any combination of 
tires up to four tires.
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    \8\ 340 F.3d 39, 54 (2d Cir. 2003).
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    Ultimately, the Court vacated the standard (FMVSS No. 138) in its 
entirety and directed the agency to issue a new rule consistent with 
its August 6, 2003 opinion. NHTSA published a final rule in the Federal 
Register on November 20, 2003, vacating FMVSS No. 138 (68 FR 65404). 
With the standard vacated, that notice clarified that, at that point in 
time, vehicle manufacturers had no certification or reporting 
responsibilities.
    In light of the foregoing, NHTSA commenced rulemaking efforts to 
reestablish FMVSS No. 138 in a manner consistent with the Court's 
opinion and responsive to the issues raised in earlier petitions for 
reconsideration, the majority of which remained relevant. To this end, 
the agency issued a second NPRM on September 16, 2004 (69 FR 55896) 
(discussed immediately below) and obtained and considered public 
comments on that NPRM, actions leading to this latest final rule for 
TPMS.
    For a more complete discussion of this earlier period of the 
regulatory history of the TPMS rulemaking, readers should consult the 
June 5, 2002 final rule and the September 16, 2004 NPRM.

III. September 2004 Notice of Proposed Rulemaking (NPRM) and Public 
Comments

A. The NPRM

    As noted above, NHTSA published an NPRM on September 16, 2004 that 
proposed to re-establish FMVSS No. 138, Tire Pressure Monitoring 
Systems, in a manner consistent with the Court's opinion. Specifically, 
it proposed to require passenger cars, multipurpose passenger vehicles, 
trucks, and buses with a GVWR of 4,536 kg (10,000 pounds) or less, 
except those with dual wheels on an axle, to be equipped with a TPMS to 
alert the driver when one or more of the vehicle's tires, up to all 
four of its tires, are significantly under-inflated. The NPRM was 
drafted so as to be technology-neutral, so as to permit compliance with 
any available TPMS technology that meets the performance requirements.
    The NPRM included the following points, which highlighted the key 
provisions of the proposed requirements.
     The TPMS would be required to warn the driver when the 
pressure in one or more of the vehicle's tires, up to a total of four 
tires, is 25 percent or more below the vehicle manufacturer's 
recommended cold inflation pressure for the tires, or a minimum level 
of pressure specified in the standard, whichever pressure is higher.
     Vehicle manufacturers would be required to certify vehicle 
compliance under the standard with the tires installed on the vehicle 
at the time of initial vehicle sale.\9\
---------------------------------------------------------------------------

    \9\ The NPRM noted that some vehicle manufacturers authorize 
their dealers to replace the vehicle's factory-installed tires with 
other tires, including ones with a different size and/or recommended 
cold tire inflation pressure. The NPRM stated that the TPMS would 
have to perform properly with any such tires, because the vehicle 
could be equipped with those tires at the time of initial sale. Of 
course, the manufacturer would not have that responsibility if the 
dealer installed other tires without manufacturer authorization. 
However, the dealer would violate the Motor Vehicle Safety Act if it 
installed tires on a new vehicle that prevented the TPMS from 
functioning properly. See 49 U.S.C. 30112(a).
---------------------------------------------------------------------------

     The TPMS would be required to include a low pressure 
telltale (yellow) that must remain illuminated as long as any of the 
vehicle's tires remains under-inflated and the vehicle's ignition 
locking system is in the ``On'' (``Run'') position. The telltale would 
be required to extinguish when all of the vehicle's tires cease to be 
significantly under-inflated. The TPMS's low tire pressure warning 
telltale would be required to perform a bulb-check at vehicle start-up.
     The TPMS also would be required to include a malfunction 
indicator to alert the driver when the system is non-operational and, 
thus, unable to provide the required low tire pressure warning. The 
NPRM proposed that TPMS malfunction could be indicated by either:
    (1) Installing a separate, dedicated telltale (yellow) that 
illuminates upon detection of the malfunction and remains continuously 
illuminated as long as the ignition locking system is in the ``On'' 
(``Run'') position and the situation causing the malfunction remains 
uncorrected, or
    (2) Designing the low tire pressure telltale so that it flashes for 
one minute when a malfunction is detected, after which the telltale 
would remain illuminated as long as the ignition locking system is in 
the ``On'' (''Run'') position. This flashing and illumination sequence 
would be repeated upon each subsequent vehicle start-up until the 
situation causing the malfunction has been corrected.
    If the option for a separate telltale is selected, the TPMS 
malfunction telltale would be required to perform a bulb-check at 
vehicle start-up.
     The TPMS would not be required to monitor the spare tire 
(if provided) either when it is stowed or when it is installed on the 
vehicle.
     For vehicles certified under the standard, vehicle 
manufacturers would be required to provide in the owner's manual an 
explanation of the purpose of the low tire pressure warning telltale, 
the potential consequences of significantly under-inflated tires, the 
meaning of the telltale when it is illuminated, and what actions 
drivers should take when the telltale is illuminated. Vehicle 
manufacturers also would be required to provide a specified statement 
in the owner's manual regarding: (1) Potential problems related to 
compatibility between the vehicle's TPMS and various replacement tires, 
and (2) the presence and operation of the TPMS malfunction indicator.
    The NPRM proposed requirements for covered vehicles manufactured on 
or after September 1, 2005 (i.e., MY 2006), subject to the following 
phase-in schedule: 50 percent of a vehicle manufacturer's light 
vehicles would be required to comply with the standard during the first 
year (September 1, 2005 to August 31, 2006); 90 percent during the 
second year (September 1, 2006 to August 31, 2007); and all vehicles 
thereafter.
    The NPRM stated that in order to encourage early compliance, the 
agency was proposing to permit carry-forward credits for vehicles that 
are certified as complying with the standard and that are manufactured 
on or after the

[[Page 18141]]

effective date of the final rule. However, under the proposal, 
beginning September 1, 2007, all covered vehicles would be required to 
comply with the standard, without regard to any earlier carry-forward 
credits.
    We proposed to exclude from the phase-in requirements final stage 
manufacturers, alterers, and small volume manufacturers (SVMs). The 
NPRM also proposed phase-in reporting requirements consistent with the 
proposed phase-in schedule.

B. Summary of Public Comments on the NPRM

    NHTSA received comments on the September 16, 2004 NPRM from a 
variety of interested parties including 10 TPMS manufacturers,\10\ 13 
automobile manufacturers and their trade associations,\11\ seven tire 
manufacturers and their trade associations,\12\ two public interest 
groups,\13\ and six other interested organizations.\14\ Comments were 
also received from 24 individuals. All of these comments may be found 
in Docket No. NHTSA-2004-19054.
---------------------------------------------------------------------------

    \10\ Comments were received from the following TPMS 
manufacturers: (1) ALPS Automotive, Inc.; (2) Aviation Upgrade 
Technologies; (3) BERU Corporation; (4) Continental Teves, Inc.; (5) 
Emtop Ltd.; (6) EnTire Solutions, LLC; (7) ETV Corporation Pty 
Limited; (8) MLHO, Inc.; (9) NIRA Dynamics AB, and (10) Schrader 
Electronics Ltd.
    \11\ Comments were received from the following automobile 
manufacturers and related trade associations: (1) Alliance of 
Automobile Manufacturers; (2) American Suzuki Motor Corporation; (3) 
Association of International Automobile Manufacturers, Inc.; (4) BMW 
of North America, LLC; (5) DaimlerChrysler Corporation; (6) 
DaimlerChrysler and Mercedes-Benz U.S.A.; (7) Fuji Heavy Industries 
USA, Inc. (makers of Subaru vehicles); (8) General Motors North 
America; (9) Honda Motor Co., Ltd. and American Honda Motor Co., 
Inc.; (10) Hyundai American Technical Center, Inc./Kia Motors 
Corporation; (11) Mitsubishi Motors R&D of America, Inc.; (12) 
Nissan North America, Inc.; (13) Porsche Cars North America, Inc., 
and (14) Volkswagen/Audi.
    \12\ Comments were received from the following tire 
manufacturers and related trade associations: (1) European Tyre and 
Rim Technical Organisation; (2) Japan Automobile Tyre Manufacturers 
Association, Inc.; (3) Rubber Manufacturers Association; (4) 
Sumitomo Rubber Industries; (5) The Tire Rack; (6) Tire and Rim 
Association, Inc., and (7) Tire Industry Association.
    \13\ Comments were received from the following public interest 
groups: (1) Advocates for Highway and Auto Safety, and (2) Public 
Citizen.
    \14\ Comments were received from the following other interested 
manufacturers, trade associations, and groups: (1) American 
Automobile Association; (2) the European Communities; (3) Fairfax 
County Public Schools; (4) GE Infrastructure Sensing; (5) National 
Automobile Dealers Association, and (6) Specialty Equipment Market 
Association.
---------------------------------------------------------------------------

    The commenters raised a variety of issues with the proposed 
requirements, including ones related to the low tire pressure warning 
lamp activation, the TPMS malfunction indicator lamp, the TPMS low 
pressure and MIL telltales, test procedures, minimum activation 
pressure requirements, the need for a tire reserve load, owner's manual 
requirements, TPMS operation with replacement tires/spare tires, lead 
time and phase-in, and other topics. The following discussion 
summarizes the main issues raised by these public comments and the 
positions expressed on these topics. A more complete discussion of the 
public comments is provided under Section IV.C, which provides an 
explanation of the agency rationale for the requirements of the final 
rule and addresses related public comments by issue.
Low Tire Pressure Warning Lamp Activation Requirements
    Regarding the activation requirements for the low tire pressure 
warning lamp, commenters raised concerns related to the NPRM's proposed 
under-inflation detection level, as well as the proposed 10-minute time 
period for under-inflation detection. Public interest groups and 
certain other commenters urged NHTSA to adopt a more stringent 
threshold for under-inflation detection (ranging from 15-20 percent 
below placard pressure). These commenters argued that existing 
technologies (i.e., direct TPMSs) can detect and warn the driver at 
lesser levels of under-inflation, thereby permitting drivers more time 
to take corrective action and maximizing the benefits provided by the 
system.
    The tire industry also urged NHTSA to adopt a more stringent under-
inflation detection threshold, with a trigger point tied to the vehicle 
placard pressure and the Gross Axle Weight Rating (GAWR). Specifically, 
the comment of TIA stated that the under-inflation detection warning 
should be triggered at 1-2 psi below the vehicle's recommended cold 
tire inflation pressure or at an inflation level where the tires can no 
longer carry the vehicle weight, whichever is higher. Other commenters 
suggested that the under-inflation detection threshold should take into 
account various vehicle loading conditions.
    Vehicle manufacturers did not comment on the under-inflation 
detection level, which suggests that they do not object to that aspect 
of the NPRM.
    Regarding the NPRM's proposed 10-minute time period for low tire 
pressure detection, vehicle manufacturers generally recommended 
extending that time period, arguing that even direct systems would 
require additional time to detect, confirm, and relay a warning about a 
significantly under-inflated tire. Comments from vehicle manufacturers 
also suggested that in order to be technology-neutral and to permit 
vehicle certification with indirect systems, the under-inflation 
detection time should be extended in situations where the vehicle has 
two, three, or four significantly under-inflated tires; those comments 
argued that there is not a safety need for rapid detection in such 
cases, where under-inflation is likely to result from diffusion over a 
considerable period of time.
    Public interest groups, the European Communities (EC), and certain 
other industry commenters argued that the proposed 10-minute detection 
time period is too long and that it would allow vehicles to continue to 
travel in a potentially unsafe condition without a warning. These 
comments suggested that such situations are unnecessary because 
technology currently exists that would permit a shorter detection time.
TPMS MIL Activation Requirements
    Regarding the time period for malfunction detection, vehicle 
manufacturers stated their concern regarding the absence in the NPRM of 
an expressed time period for the TPMS to detect a malfunction and to 
illuminate the TPMS MIL. Commenters stated that immediate detection, as 
implied by the NPRM, is not technically possible and that in most 
cases, the vehicle must be driven in order to detect a malfunction. 
Several commenters stated that TPMSs cannot detect malfunctions any 
faster than the system can detect low tire pressure (because the same 
subsystems are involved) and that the same durational parameters should 
be set for both functions (with suggestions ranging from 20-30 
minutes).
    A number of manufacturers commented that the proposed TPMS 
malfunction requirements are overly broad and are in need of 
modification. Specific commenters asserted that TPMSs would have 
difficulties detecting or reporting various types of malfunctions.
    One commenter raised the issue of MIL disablement (or suppression) 
in situations where the TPMS sending units have been removed as a 
result of the replacement of the original equipment tires and rims with 
aftermarket components that are not compatible with the direct-sensing 
TPMS. (The NPRM made no provision for MIL disablement.)
Telltale Requirements
    A number of commenters discussed the issue of how the TPMS MIL 
would operate, particularly when it is combined with the low tire 
pressure warning telltale. Some commenters,

[[Page 18142]]

primarily representing vehicle manufacturers, argued that the MIL 
requirements are design-restrictive and may impose unnecessary costs. 
Those commenters requested flexibility in providing the malfunction 
warning through a variety of means (e.g., text messaging and audible 
warnings), provided that the warning is explained in the vehicle 
owner's manual.
    Several commenters expressed concern about how the malfunction 
warning would be provided to the driver in a combined telltale. Some 
commenters argued that flashing should be used to indicate low tire 
pressure; some argued that flashing should be used to indicate 
malfunction; some argued that the flashing sequence should be longer, 
and still others argued that any sort of flashing may be confusing to 
drivers.
    Public interest groups generally favored requiring a separate 
telltale to indicate TPMS malfunction, in order to provide a clear 
message to drivers. However, manufacturers commented that separate 
telltales are unnecessary, add cost, and consume valuable space on the 
instrument panel that could be used to provide other safety messages.
    Commenters overwhelmingly recommended that NHTSA reconsider its 
proposed symbol to indicate a TPMS malfunction, which was considered to 
be confusing, and a variety of alternatives were suggested. Some 
commenters expressed support for only permitting a low tire pressure 
telltale that indicates which tire is under-inflated, because such 
symbol is both more recognizable and offers enhanced information to the 
driver.
    Regarding telltale color, some manufacturers recommended permitting 
the low tire pressure telltale to change color (e.g., from yellow to 
red) to indicate when under-inflation has progressed to a dangerously 
low level, as determined by the vehicle manufacturer. Commenters also 
raised the issue of the color of the TPMS MIL, with some recommending 
yellow and others recommending red.
    In their comments, manufacturers also raised issues related to 
extinguishment of the TPMS telltales. For example, concerns were raised 
regarding the possibility of a TPMS reset button extinguishing the 
telltale before the underlying problem (i.e., low tire pressure or 
system malfunction) has been corrected. Others suggested that the final 
rule should specify that tires must be re-inflated to a level at least 
10 percent above the warning threshold before the TPMS low pressure 
telltale would extinguish.
    Another topic raised by commenters related to the TPMS combined 
telltale involved requests for the final rule to set an illumination 
priority for the low tire pressure and TPMS malfunction warnings. 
Commenters did not agree as to which warning should take precedence.
Tire-Related Issues
    Another major area of comment involved tire issues. Regarding the 
issue of the NPRM's proposed approach for TPMS operation with 
replacement and spare tires, public interest groups generally objected 
to the agency's tentative decision to require compliance certification 
with the tires originally installed on the vehicle, but to require a 
malfunction indicator to indicate to the driver when replacement tires 
have been installed on the vehicle which prevent the continued proper 
functioning of the TPMS. Those commenters suggested that the TPMS 
should either be required to function with all replacement tires and 
original equipment (OE) full-sized spare tires (so as to provide 
continuing operational benefits to consumers) or that there should be 
ongoing efforts to make the public aware of those tires which have been 
found to prevent proper TPMS functioning.
    Comments from the tire industry also supported a requirement for 
the TPMS to operate with replacement tires, particularly in light of 
those tires' prevalence in the marketplace. Those commenters further 
argued that vehicle manufacturers should be required to provide 
affordable access to TPMS service information to all tire dealers and 
service providers. Other commenters expressed concern regarding the 
impact the proposed rule would have on small businesses.
    The tire industry recommended that the final rule should include a 
tire pressure reserve requirement in order to ensure that the vehicle 
can safely carry the vehicle maximum load, even if the tires are under-
inflated by 25 percent below placard pressure. Otherwise, commenters 
argued that the vehicle's tires may fall below the level designated in 
the tire industry's load/pressure tables but still not trigger a low 
pressure warning from the TPMS. These commenters were especially 
concerned that this situation could lead to increased instances of tire 
failure, particularly if drivers come to rely on the TPMS as a 
substitute for regular tire maintenance. Moreover, the Tire and Rim 
Association (TRA) stated its intention to modify its 2005 Year Book to 
provide additional instruction for manufacturers of TPMS-equipped 
vehicles.
    The Alliance commented that the NPRM's proposed Table 1, which 
specifies minimum activation pressures for different tires, should be 
modified for Load Range ``C,'' ``D,'' and ``E'' light truck (LT) tires. 
According to the Alliance, the MAPs currently contained in Table 1 do 
not allow such tires to be used across the safe operating ranges of 
inflation pressures for which loads are specified in the TRA Yearbooks. 
The Alliance argued that unless corrective action is taken, vehicle 
manufacturers could face costly vehicle redesigns or be forced to 
substitute less capable tires in certain vehicle applications.
Owner's Manual Requirements
    Several commenters suggested modifications to the NPRM's proposed 
language related to TPMSs for the vehicle owner's manual. One comment 
involved allowing vehicle manufacturers discretion to tailor the 
owner's manual statement to the system installed on the vehicle, 
provided that certain basic topics were addressed. Other comments 
included clarifying the discussion of permissible telltale formats, of 
proper pressures for replacement wheel/tire combinations, and of 
ongoing driver responsibility for maintaining proper tire inflation 
pressure.
Test Procedures
    Commenters raised a number of issues related to the NPRM's proposed 
test conditions and procedures. The issue of calibration time was 
raised, with at least one manufacturer commenter suggesting that no 
calibration period is necessary, and other manufacturer commenters 
arguing that the NPRM's proposed 20-minute calibration time should be 
extended to 30 minutes or one hour.
    Comments from the tire industry recommended that the test 
conditions and performance parameters in the final rule should be 
expanded to capture a fuller range of real world driving conditions. 
Specifically, these comments recommended expanding the proposed ambient 
temperature range to include colder and warmer temperatures, testing 
under slippery road conditions, and expanding the vehicle speed range 
to include both slower and faster speeds.
    Commenters also offered suggestions pertaining to the test 
procedures for TPMS MIL activation, which would implement their 
recommendations regarding the types of malfunctions the system should 
be required to detect and how quickly they should be detected.

[[Page 18143]]

    Manufacturers also commented on the proposed cool-down period of up 
to one hour, as contained in S6(e) of the proposed test procedures. The 
Alliance recommended reducing the cool-down period to five minutes or 
less, arguing that in certain cases, tires deflated during testing when 
cold may warm up to a point above the warning threshold before the TPMS 
has time to detect a significantly under-inflated tire. Other 
commenters made similar arguments and recommended adding additional 
pressure checks to the test procedures to ensure that the pressure 
level has been set accurately during testing.
    Other commenters urged NHTSA to modify the test procedures to 
recognize that testing may need to be conducted with a pressure other 
than placard pressure in order to properly match the load on the tires. 
These comments suggested that the owner's manual should be consulted in 
order to select the proper pressure under certain situations.
    Several commenters also raised issues regarding use of a system 
reset feature during testing, including use in situations where the 
driver switches between summer and winter tires.
Lead Time and Phase-In
    In general, most of the vehicle manufacturers that commented on the 
NPRM requested additional lead time and a modified phase-in schedule, 
arguing that more time is necessary to incorporate TPMS technologies 
into their new vehicle production processes. Most vehicle manufacturer 
commenters recommended a two-year phase-in, with an initial compliance 
date beginning on September 1, 2006. Furthermore, vehicle manufacturers 
universally commented that it would not be possible to incorporate the 
TPMS MIL until September 1, 2007.
    In contrast, public interest groups expressed support for the 
NPRM's compliance schedule, as proposed.
Other Issues
    Commenters also raised a variety of other issues in response to the 
NPRM. These included small business impacts, environmental impacts, 
maintenance issues, markings on vehicles equipped with direct TPMSs, 
definitions, educational efforts, alternative systems, over-inflation 
detection, temperature and altitude compensation, system longevity, and 
harmonization. Comments on each of these issues will be described and 
addressed in section IV.C of this notice.

IV. The Final Rule and Response to Public Comments

A. Summary of the Requirements

    After careful consideration of public comments on the NPRM, this 
final rule re-establishes FMVSS No. 138, Tire Pressure Monitoring 
Systems, in a manner consistent with the Second Circuit's opinion. 
Specifically, it requires passenger cars, multi-purpose passenger 
vehicles, trucks, and buses with a GVWR of 4,536 kg (10,000 pounds) or 
less, except those with dual wheels on an axle, to be equipped with a 
TPMS to alert the driver when one or more of the vehicle's tires, up to 
all four of its tires, is significantly under-inflated. Subject to the 
phase-in schedule and the exceptions below, compliance with the 
requirements of the final rule commences for covered vehicles 
manufactured on or after October 5, 2005 (i.e., MY 2006). The standard 
is intended to be technology-neutral, so as to permit compliance with 
any available TPMS technology that meets the standard's performance 
requirements.
    The following points highlight the key provisions of the final 
rule.
     The TPMS is required to detect and to provide a warning to 
the driver within 20 minutes of when the pressure of one or more of the 
vehicle's tires, up to a total of four tires, is 25 percent or more 
below the vehicle manufacturer's recommended cold inflation pressure 
for the tires, or a minimum level of pressure specified in the 
standard, whichever pressure is higher. These minimum activation 
pressures are included in Table 1 of FMVSS No. 138.\15\
---------------------------------------------------------------------------

    \15\ We note that the Alliance of Automobile Manufacturers 
submitted a Petition for Rulemaking on April 29, 2003 that asks 
NHTSA to make certain changes to the MAPs in Table 1 (see Docket No. 
NHTSA-2000-8572-265). For a more complete discussion of the MAP 
issue raised by the Alliance, see section IV.C.4.d of this document. 
NHTSA is in the process of evaluating the issues raised in the 
Alliance petition. However, we have decided to modify the values in 
Table 1 pertaining to Load Range ``D'' and ``E'' tires, pending 
completion of our analysis.
---------------------------------------------------------------------------

     Vehicle manufacturers must certify vehicle compliance 
under the standard with the tires installed on the vehicle at the time 
of initial vehicle sale.\16\
---------------------------------------------------------------------------

    \16\ We note that some vehicle manufacturers authorize their 
dealers to replace the vehicle's factory-installed tires with other 
tires, including ones with a different size and/or recommended cold 
tire inflation pressure. The TPMS must perform properly with any 
such tires, because the vehicle could be equipped with those tires 
at the time of initial sale. Of course, the manufacturer would not 
have that responsibility if the dealer installed other tires without 
manufacturer authorization.
---------------------------------------------------------------------------

     The TPMS must include a low tire pressure warning telltale 
\17\ (yellow) that must remain illuminated as long as any of the 
vehicle's tires remain significantly under-inflated and the vehicle's 
ignition locking system is in the ``On'' (``Run'') position.\18\ The 
TPMS's low tire pressure warning telltale must perform a bulb-check at 
vehicle start-up.
---------------------------------------------------------------------------

    \17\ As part of this final rule, we are adding two versions of 
the TPMS low tire pressure telltale and a TPMS malfunction telltale 
to Table 2 of FMVSS No. 101, Controls and Displays. The regulatory 
text in this final rule incorporates the TPMS telltales in Table 2, 
as that table currently exists in the Code of Federal Regulations. 
However, we note that NHTSA published an NPRM in the Federal 
Register on September 23, 2003 that proposes to update and to expand 
FMVSS No. 101 (68 FR 55217). Publication of the present version of 
Table 2 here is not intended to suggest a change in approach to the 
ongoing FMVSS No. 101 rulemaking. We anticipate incorporating the 
TPMS telltales in a revised Table 2, once a final decision is 
reached on updating Standard No. 101.
    \18\ We note that if a vehicle manufacturer elects to install a 
low tire pressure telltale that indicates which tire is under-
inflated, the telltale must correctly identify the under-inflated 
tire. See S4.3.2.
---------------------------------------------------------------------------

     The TPMS must also include a TPMS malfunction indicator to 
alert the driver when the system is non-operational, and thus unable to 
provide the required low tire pressure warning.\19\ The TPMS 
malfunction indicator must detect a malfunction within 20 minutes of 
occurrence and provide a warning to the driver. This final rule 
provides two options by which vehicle manufacturers may indicate a TPMS 
malfunction:
---------------------------------------------------------------------------

    \19\ We note that the TPMS telltale(s) may be incorporated as 
part of a reconfigurable display, provided all requirements of the 
standard are met.
---------------------------------------------------------------------------

    (1) Installation of a separate, dedicated telltale (yellow) that 
illuminates upon detection of the malfunction and remains continuously 
illuminated as long as the ignition locking system is in the ``On'' 
(``Run'') position and the situation causing the malfunction remains 
uncorrected, or
    (2) Designing the low tire pressure telltale so that it flashes for 
a period of at least 60 seconds and no longer than 90 seconds when a 
malfunction is detected, after which the telltale must remain 
continuously illuminated as long as the ignition locking system is in 
the ``On'' (``Run'') position. This flashing and illumination sequence 
must be repeated upon each subsequent vehicle start-up until the 
situation causing the malfunction has been corrected.

    If the option for a separate telltale is selected, the TPMS 
malfunction telltale must perform a bulb-check at vehicle start-up.
     The TPMS is not required to monitor the spare tire (if 
provided),

[[Page 18144]]

either when it is stowed or when it is installed on the vehicle.
     For vehicles certified under the standard, vehicle 
manufacturers must provide in the owner's manual a specified statement 
explaining the purpose of the low tire pressure warning telltale, the 
potential consequences of significantly under-inflated tires, the 
meaning of the telltale when it is illuminated, and what actions 
drivers should take when the telltale is illuminated. Vehicle 
manufacturers also must provide a specified statement in the owner's 
manual regarding: (1) potential problems related to compatibility 
between the vehicle's TPMS and various replacement or alternate tires 
and wheels, and (2) the presence and operation of the TPMS malfunction 
indicator. For vehicles that do not come with an owner's manual, the 
required information must be provided in writing to the first purchaser 
at the time of initial vehicle sale.

B. Lead Time and Phase-In

    As discussed in the NPRM, the Second Circuit's decision vacating 
FMVSS No. 138 necessitated a change in the standard's phase-in schedule 
in order to ensure the practicability of the standard's implementation, 
particularly for those manufacturers that had intended to certify to 
the June 5, 2002 final rule's one-tire, 30-percent option. Responses to 
the agency's September 9, 2003 Special Orders to 14 vehicle 
manufacturer and 13 TPMS suppliers demonstrated that in anticipation of 
the start of the phase-in under the June 2002 final rule, most vehicle 
manufacturers were moving aggressively toward installation of TPMSs 
capable of meeting the four-tire, 25-percent detection requirement, 
although some were not. The information provided by TPMS suppliers 
indicated sufficient capacity to supply TPMSs with a four-tire, 25-
percent detection capability in quantities that would easily meet the 
phase-in requirements. Accordingly, in the NPRM, the agency proposed 
that 50 percent of a vehicle manufacturer's light vehicles would be 
required to comply with the standard during the first year (September 
1, 2005 to August 31, 2006); 90 percent during the second year 
(September 1, 2006 to August 31, 2007); and all vehicles thereafter.
    In public comments on the NPRM, vehicle manufacturers argued that 
they would not be able to meet the standard's requirements given the 
proposed lead time and phase-in schedule. Most of their concerns 
involved the TPMS malfunction indicator, a newly proposed requirements 
which manufacturers uniformly agreed would necessitate significant 
engineering and vehicle design efforts and corresponding production 
changes. Vehicle manufacturers stated that they could meet the TPMS MIL 
requirements (and associated owner's manual requirements) by September 
1, 2007. More generally, vehicle manufacturers commented that, setting 
aside the issue of the MIL requirements, the phase-in schedule 
nevertheless may be too aggressive.
    We acknowledge that the TPMS MIL represents a new requirement 
impacting TPMS design and functionality and that vehicle manufacturers 
may require additional time to incorporate the MIL into their 
production processes. However, we do not believe that implementation of 
the entire standard should be delayed until technical changes related 
to the TPMS MIL can be fully resolved, because that would deny the 
public the safety benefits of TPMSs in the meantime. Accordingly, we 
believe that it is preferable to move rapidly to implement the 
standard, but to delay the compliance date only for the TPMS MIL 
requirements and associated requirements in the owner's manual.
    In light of the above and subject to the vehicle manufacturer 
option for carry-backward credits discussed below, NHTSA has decided to 
adopt the following phase-in schedule: 20 percent of a vehicle 
manufacturer's light vehicles are required to comply with the standard 
during the period from October 5, 2005, to August 31, 2006; 70 percent 
during the period from September 1, 2006 to August 31, 2007, and all 
light vehicles thereafter. However, vehicle manufacturers are not 
required to comply with the requirements related to the TPMS 
malfunction indicator (including associated owner's manual 
requirements) until September 1, 2007; however, at that point, all 
covered vehicles must meet all relevant requirements of the standard 
(i.e., no additional phase-in for MIL requirements). The final rule 
includes phase-in reporting requirements consistent with the phase-in 
schedule discussed above.
    Small volume manufacturers (i.e., those manufacturers producing 
fewer than 5,000 vehicles for sale in the U.S. per year during the 
phase-in period) are not subject to the phase-in requirements, but 
their vehicles must meet the requirements of the standard beginning 
September 1, 2007.
    Consistent with the policy set forth in NHTSA's February 14, 2005 
final rule on certification requirements for vehicles built in two or 
more stages and altered vehicles (70 FR 7414), final-stage 
manufacturers and alterers must certify compliance for covered vehicles 
manufactured on or after September 1, 2008. However, final-stage 
manufacturers and alterers may voluntarily certify compliance with the 
standard prior to this date.
    NHTSA has decided to permit vehicle manufacturers to earn carry-
forward credits for compliant vehicles, produced in excess of the 
phase-in requirements, that are manufactured between the effective date 
of this rule and the conclusion of the phase-in. These carry-forward 
credits could be used during the phase-in, but they could not be used 
to delay compliance certification for vehicles produced after the 
conclusion of the phase-in. Except for vehicles produced by final-stage 
manufacturers and alterers (who receive an additional year for 
compliance), all covered vehicles must comply with FMVSS No. 138 on 
September 1, 2007, without use of any carry-forward credits.
    Furthermore, we have determined that there is good cause to make 
this final rule effective upon publication so that vehicle 
manufacturers would have a standard in effect to which they may certify 
vehicles for purposes of early, voluntary compliance and to maximize 
the time for earning carry-forward credits. We explicitly note that 
vehicle manufacturers have no mandatory compliance responsibilities 
under the standard until the start of the phase-in.
    To further ease implementation, we have decided to also provide 
carry-backward credits, whereby vehicle manufacturers may defer 
compliance with a part or all of the certification requirements for the 
first period of the phase-in, provided that they certify a 
correspondingly larger percentage of vehicles under the standard during 
the second period of the phase-in. We believe that permitting carry-
backward credits would not impact the overall safety benefits of the 
final rule, because the same number of vehicles would be subject to 
compliance certification, although the distribution may vary over the 
model years of the phase-in. Corresponding changes have been added to 
the regulatory text of both FMVSS No. 138, as well as the TPMS phase-in 
requirements contained in 49 CFR Part 585.

C. Response to Public Comments by Issue

    As noted previously, public comments on the September 2004 NPRM for 
TPMS raised a variety of issues with the NPRM's proposed requirements. 
Each of these topics will be discussed in turn, in order to explain

[[Page 18145]]

how these comments impacted the agency's determinations in terms of 
setting requirements for this final rule.
1. Low Tire Pressure Warning Lamp Activation Requirement
    (a) Under-Inflation Detection Level. The NPRM proposed to require 
the TPMS to illuminate a low tire pressure warning telltale not more 
than 10 minutes after the inflation pressure in one or more of the 
vehicle's tires, up to a total of four tires, is equal to or less than 
the pressure 25 percent below the vehicle manufacturer's recommended 
cold inflation pressure or the pressure specified in the 3rd column of 
Table 1 of this standard for the corresponding tire type, whichever is 
higher (see S4.2(a)).
    A number of commenters raised concerns about the 25-percent under-
inflation detection level proposed in the NPRM. Although their 
reasoning differed, these commenters all argued that a more stringent 
detection level should be required under the final rule.
    Public Citizen stated that a 20-percent threshold should be 
adopted. Public Citizen argued that NHTSA's technology-neutral 
standard, as proposed, was crafted to accommodate indirect TPMSs (which 
Public Citizen considers to be an ``inferior technology'') when there 
is other adequate technology readily available (i.e., direct TPMSs). 
(Advocates for Highway and Auto Safety (Advocates) provided a similar 
comment.) According to Public Citizen, NHTSA should not reduce safety 
requirements in order to accommodate inferior technology, particularly 
when other affordable and more effective technology exists.
    Public Citizen stated that the aspect of the agency's rationale 
that a higher threshold could discourage technological innovation is 
unsubstantiated. The comments of Public Citizen similarly characterized 
as unsubstantiated NHTSA's concerns about nuisance warnings that could 
result from a detection level that is set too close to placard pressure 
and requested substantive driver behavioral research to confirm that 
this would be a problem. (Similarly, Advocates argued that NHTSA acted 
arbitrarily in selecting a 25-percent under-inflation threshold (as 
opposed to the 20-percent level proposed in the 2001 NPRM) and that the 
record does not justify NHTSA's claim that a 20-percent under-inflation 
detection level would result in nuisance warnings.)
    Public Citizen rounded out its comments in this area by 
characterizing the NPRM's 25-percent under-inflation detection level as 
a cost-saving measure. It argued that safety should outweigh cost 
considerations and that NHTSA's other rulemaking activities provided 
support for adopting a 20-percent under-inflation detection level 
(e.g., the 2001 TPMS NPRM and the agency's rollover research). The 
Advocates argued that NHTSA has not compared the actual benefits of the 
two thresholds and suggested that NHTSA's New Car Assessment Program 
(NCAP) data would support the theory that different pressure levels 
correlate with different levels of risk.
    Fairfax County Public Schools expressed support for a system that 
either provides a built-in tire pressure gauge or provides an earlier 
warning, such as a 20-percent under-inflation detection level. It 
stated that it is not always easy to find a functioning air compressor 
when traveling, so it is better to provide an earlier indication before 
the vehicle is past the point of safe operation.
    Mr. James Anderson, an individual, commented that the under-
inflation detection level should be set at some point between 15 
percent and 18 percent below placard pressure, the point at which the 
commenter argued that the tire sidewall begins to over-flex. According 
to Mr. Anderson, as the tire over-flexes, heat begins to build up, but 
the tire is no longer able to dissipate the heat. Mr. Anderson stated 
that at some point above 200 [deg]F, the tire compounds begin a 
reversion process, which may lead to delamination and, ultimately, 
separation of tire components. He argued that a warning level 25-
percent below placard pressure would not permit sufficient time for 
driver recognition and timely action to correct the under-inflation 
situation before tire damage may occur.
    The Tire Industry Association (TIA) argued that the proposed TPMS 
under-inflation detection level is too lenient, suggesting that the 
trigger point instead should be tied to the vehicle's placard pressure 
and GAWR. Specifically, TIA stated that the under-inflation detection 
warning should be triggered at 1-2 psi below the vehicle's recommended 
cold tire inflation pressure or at an inflation level where the tires 
can no longer carry the vehicle weight, whichever is higher. (TIA's 
argument here is related to the issue of Tire Reserve Load, a topic 
discussed later in this document.) TIA argued that the standard should 
require the TPMS to provide a warning before there is a serious 
problem, thereby taking into account that drivers may not immediately 
take corrective action when the warning telltale illuminates.
    ETV Corporation (ETV) stated that the TPMS should be required to 
take into account different load conditions in determining the need to 
activate the low tire pressure warning.
    The National Automobile Dealers Association (NADA) stated that 
although the final rule must factor in technological and cost 
constraints, it should specify the smallest under-inflation threshold 
that can be reliably monitored.
    EnTire Solutions, LLC (EnTire) commented that the direct TPMSs it 
produces are capable of providing low pressure warnings at a more 
stringent threshold than the NPRM's proposed 25-percent under-inflation 
detection level. EnTire also stated that its system and those of other 
TPMS manufacturers have multiple thresholds for under-inflation 
detection. GE Infrastructure Sensing stated that technology currently 
exists for TPMSs to detect a 20-percent under-inflation level.
    The Tire Rack argued that the 25-percent under-inflation detection 
level does not provide an adequate and timely warning to the driver and 
may provide a false sense of security. The Tire Rack also stated that, 
to the extent the 25-percent under-inflation detection level reflects 
limitations of current technology, the final rule should establish 
successively more stringent requirements in order to ensure future 
improvements in TPMS technology. It argued that establishing goals and 
timetables as part of the final rule would encourage technological 
developments for TPMSs.
    The American Automobile Association (AAA) stated that the NPRM 
proposes to set the under-inflation warning threshold at a level that 
is insufficiently stringent, because a tire that is 25 percent below 
the manufacturer's recommended inflation pressure could already present 
a dangerous situation, particularly if the vehicle is in a fully-loaded 
condition. AAA argued that under-inflated tires ``produce increased 
heat, which is a major cause of failure.'' According to AAA, an 
effective TPMS is one that provides a warning before a dangerous 
situation is imminent and which does not mislead motorists into 
equating the absence of an illuminated warning light with safety.
    BERU Corporation (BERU) commented that the under-inflation 
detection level should be set to trigger a warning at either 25-percent 
below placard pressure or a minimum activation pressure of 1.4 bar.
    The Rubber Manufacturers Association (RMA) commented that lost fuel 
efficiency was not adequately accounted for in the assessment of 
economic costs when selecting an

[[Page 18146]]

under-inflation detection threshold. The RMA asserted that the NPRM's 
benefits calculations indicated that 26 percent of vehicles have tires 
that are under-inflated below placard pressure, but that associated 
fuel efficiency costs were not considered.
    The Specialty Equipment Market Association (SEMA) argued that TPMSs 
should be reprogrammable in order to accommodate alternate and 
replacement tires with different pressure thresholds, or alternatively, 
the system could include ``smart'' software that would automatically 
detect the proper pressure threshold. According to SEMA, as currently 
proposed, when a higher-pressure tire is installed on the vehicle, the 
TPMS would not indicate low tire pressure until the tire is 25-percent 
below the value for the lower-pressure, original tire, and the converse 
would also be a problem, with the telltale actuating prematurely when a 
lower-pressure aftermarket tire is installed. SEMA stated that this 
situation would defeat the intent of the rule, give drivers a false 
sense of security, and be potentially problematic for new, low-profile 
tires that may be easily damaged.
    As part of the final rule, we have decided to retain the proposed 
under-inflation detection level, by which the TPMS is required to 
illuminate a low tire pressure warning telltale whenever the inflation 
pressure in one or more of the vehicle's tires, up to a total of four 
tires, is equal to or less than their the pressure 25 percent below the 
vehicle manufacturer's recommended cold inflation pressure or the 
pressure specified in the 3rd column of Table 1 of this standard for 
the corresponding tire type, whichever is higher. We have reached this 
determination for the following reasons.
    Selecting an appropriate notification threshold level for the TPMS 
is one of the most fundamental matters to be resolved as part of this 
rulemaking. It involves balancing the safety benefits of alerting 
consumers to low tire pressure against the risks of over-alerting them 
to the point where the warning becomes a nuisance that may be ignored. 
We believe that the final rule's 25-percent under-inflation detection 
level strikes the proper balance in this regard.
    As discussed in the June 5, 2002 final rule, NHTSA conducted a tire 
pressure survey that inspected over 11,500 vehicles, which reported 
that 26 percent of passenger cars and 29 percent of light trucks had at 
least one tire that was 25 percent or more below the recommended 
inflation pressure for that vehicle (see 67 FR 38704, 38713). However, 
despite this substantial percentage of vehicles with under-inflated 
tires at this level, incidents of tire failures remain infrequent. 
NHTSA conducted testing on a variety of Standard Load P-metric tires at 
20 psi with 100-percent load at 75 mph for 90 minutes on a dynamometer, 
and none of these tires failed (see 67 FR 38704, 38726 (June 5, 2002)). 
This testing led the agency to conclude that warnings at less severe 
conditions will give drivers sufficient time to check and re-inflate 
their vehicles' tires before the tires experience appreciable damage. 
Accordingly, we believe that an under-inflation detection level of 25 
percent would have a strong fleet impact, holding driver behavior 
constant.
    However, if we instead selected an under-inflation detection 
threshold that is too stringent, with some commenters arguing for a 
level as small as 1 or 2 psi below placard pressure, the warning 
telltale might illuminate frequently, and the driver would need to 
repeatedly stop and add a small amount of air to the tires in order to 
extinguish the telltale. After servicing the tires in this manner for 
the first few times, the driver might decide to postpone action on the 
TPMS's warnings or ignore such warnings entirely. Thus, if the under-
inflation warning threshold were to be set too low, the safety benefits 
associated with the TPMS's low pressure warning could be lost. Because 
we have determined that a 25-percent under-inflation detection 
threshold already provides a warning to the driver before adverse 
safety consequences arise, providing a more stringent warning threshold 
would not be expected to provide additional safety benefits, although 
it could increase the risk of the nuisance warnings discussed above.
    We disagree with Public Citizen's reading of the Court's decision 
in Public Citizen v. Mineta, implying that the Court had somehow ruled 
against NHTSA's development of a technology-neutral standard or its 
consideration of costs as a part of the rulemaking. In fact, the Court 
held that it was appropriate for NHTSA to consider costs as part of the 
rulemaking, stating ``the agency was correct to consider the relative 
costs,''\20\ although the Court disagreed with how the agency weighed 
those costs in setting compliance options in the June 2002 final rule. 
Furthermore, the Court specifically found the four-tire, 25-percent 
under-inflation detection level to be reasonable. The Court held, 
``Given that the 25 percent standard was a substantially more cost 
effective means of preventing injuries and saving lives than the 20 
percent standard, we conclude that it was reasonable for NHTSA to adopt 
the former and reject the latter.''\21\
---------------------------------------------------------------------------

    \20\ Public Citizen v. Mineta, 340 F.3d 39, 57 (2d Cir. 2003).
    \21\ Id. at 62.
---------------------------------------------------------------------------

    Available agency data show that a TPMS with a four-tire, 25-percent 
under-inflation threshold is more cost-effective than one with a four-
tire, 20-percent under-inflation threshold. This issue was specifically 
addressed in the Final Economic Assessment (FEA) for the June 2002 
final rule, which found that the net cost per equivalent life saved for 
a four-tire, 20-percent system would be $5.1-$5.3 million but that the 
net cost per equivalent life saved for a four-tire, 25-percent system 
would be $4.3 million.\22\ Although we realize that the precise values 
of these figures are somewhat outdated, we believe that their cost-
effectiveness relative to each other has not changed significantly. For 
additional information on the cost of alternative systems considered, 
please consult the FEA and the Final Regulatory Impact Analysis (FRIA) 
for this final rule, which has been included in the docket for this 
rulemaking.
---------------------------------------------------------------------------

    \22\ See page iv of the FEA (Docket No. NHTSA-2000-8572-216).
---------------------------------------------------------------------------

    We are not adopting BERU's recommendations regarding the under-
inflation detection test procedures because BERU has not provided any 
rationale to explain why the existing procedures are inadequate.
    Regarding the issue of TPMS reprogrammability raised by SEMA, we 
have decided to permit, but not require, such a feature. However, we 
reiterate that we will conduct compliance testing with the tires 
installed on the vehicle at the time of initial sale, and we will 
follow manufacturer instructions for resetting the TPMS.
    (b) Time Period for Low Pressure Detection. As noted above, 
paragraph S4.2(a) of the NPRM proposed to require the TPMS to detect 
and provide a warning to the driver within 10 minutes after a tire 
becomes significantly under-inflated (i.e., reaches the warning 
threshold specified in the standard). Under paragraph S4.2(b), the NPRM 
proposed to require the low pressure telltale to continue to illuminate 
as long as the pressure in any of the tires is equal to or less than 
the activation threshold specified in S4.2(a) and the ignition locking 
system is in the ``On'' (``Run'') position, whether or not the engine 
is running. The NPRM proposed that the telltale must extinguish after 
the inflation pressure is corrected.
    A number of commenters urged NHTSA to modify this ten-minute 
detection time requirement as part of

[[Page 18147]]

the final rule, with some commenters recommending a longer time period 
and others recommending a shorter one.
    Manufacturers that commented on low pressure detection time 
generally recommended extending the time period. BMW of North America, 
LLC (BMW) stated that the TPMS requirements should reflect real world 
needs. As a result, BMW stated that the NPRM's 10-minute detection 
requirement should be retained when only one tire becomes significantly 
under-inflated (e.g., to detect situations where a tire is punctured by 
a nail or sustains other damage that could result in a relatively rapid 
loss of inflation pressure). BMW stated that when two, three, or all 
four tires become significantly under-inflated at the same time, the 
detection time requirement should be extended to 90 minutes, because 
under-inflation in these circumstances is likely to result from slow 
diffusion over months and is not likely to result in a problem 
requiring immediate attention. NIRA Dynamics provided similar arguments 
and reasoning, although it recommended a detection time of 20 minutes 
for a single tire and at least one hour for multiple tires.
    Sumitomo Rubber Industries (Sumitomo) offered a different 
assessment of the time needed for low pressure detection. Sumitomo 
stated that it is appropriate to maintain a 10-minute detection (and 
extinguishment) requirement for one tire, but that a TPMS would need at 
least 30 minutes (preferably one hour) to detect (and extinguish) 
multiple under-inflated tires.
    In its comments, Hyundai American Technical Center, Inc./ Kia 
Motors Corporation (Hyundai) provided yet another recommendation 
regarding low tire pressure detection time, stating that the time 
period for detection and verification of low tire pressure under the 
standard should be extended to at least 20 minutes. Hyundai stated that 
delivery frequency for data from the direct TPMS tire pressure sensor 
to the main control unit can take as long as three minutes, which is a 
function of Federal Communications Commission (FCC) requirements \23\ 
that limit signal transmissions and the capacity of the battery in the 
sensor. In addition, Hyundai stated that a number of transmissions may 
be required to correctly diagnose low tire pressure. Therefore, if a 
wireless data error occurs, Hyundai argued that the TPMS may not be 
able to gather sufficient data within the NPRM's proposed 10-minute 
time limit to assess the vehicle's tire pressures. Accordingly, Hyundai 
argued that the final rule should permit at least 20 minutes for low 
tire pressure detection in order to give the TPMS sufficient time to 
gather enough data to make an accurate assessment.
---------------------------------------------------------------------------

    \23\ See 47 CFR 15.231.
---------------------------------------------------------------------------

    Volkswagen of America, Inc., Volkswagen AG, and Audi AG (VW/Audi) 
commented that in order to overcome the technology-limiting 
requirements of the NPRM, the final rule should permit a driving time 
of up to one hour for the low tire pressure warning, a time period 
consistent with detecting the unlikely situation where all four tires 
become under-inflated due to slow air leakage or changes in ambient 
temperature.
    In contrast, other commenters argued that the NPRM's 10-minute 
under-inflation detection time is too long and should be reduced. 
Public Citizen argued that the requirement for under-inflation 
detection time should be reduced to one minute in the final rule, 
because direct TPMSs can meet such a requirement. Public Citizen stated 
that in proposing a 10-minute under-inflation detection requirement, 
NHTSA has unjustifiably lowered the bar in order to accommodate more 
manufacturers (i.e., to permit indirect TPMSs requiring a longer time 
period for detection).
    ETV commented that the TPMS should be required to activate (and 
extinguish) its warning within 10 seconds of vehicle start-up in order 
to prevent the vehicle from entering traffic with a potentially 
dangerous level of tire under-inflation.
    The EC commented that the 10-minute detection time for the low tire 
pressure warning does not adequately address the tire safety problem, 
because during this period, the tire(s) may be operated at pressures 
even lower than 25-percent below the recommended pressure and 
significant structural damage could occur during that time period. The 
EC expressed concern that a combination of high speed, a long 
activation period, and a 25-percent under-inflation detection level 
could significantly reduce the time available to the driver to take 
appropriate action. (The European Tyre and Rim Technical Organisation 
(ETRTO) provided a similar comment.) The RMA similarly objected to the 
10-minute activation time period as being unsafe; the RMA argued that, 
particularly at higher speeds, that activation time would allow the 
vehicle to travel with under-inflated tires for many miles with 
excessive heat, over-deflected body cords, and possible structural 
damage.
    According to Emtop Ltd. (Emtop), the NPRM's 10-minute under-
inflation detection requirement does not address the 15 percent of 
incidents of under-inflation caused by rapid pressure drop (Emtop's 
estimate). Emtop argued that the proposed requirement is dictated by 
the inability of many current systems to meet a more stringent 
requirement for detection time. Emtop stated that its TPMSs can detect 
rapid pressure losses ``in a fraction of a second'' and that the TPMS 
rule should not create barriers to such high-performance systems.
    MLHO, Inc. (MLHO), which has developed a battery-less, non-radio-
frequency (RF) TPMS that relies on directional magnetic coupling to 
send pressure information, commented that there is no need for a TPMS 
to provide either an under-inflation warning or a malfunction warning 
while the vehicle is stationary. (In simple terms, in the MLHO TPMS 
system, wheel rotation powers the transmitter.) The commenter argued 
that a very flat tire will be obvious to the driver or will trigger the 
warning before the vehicle has traveled a significant distance. As to 
the malfunction indication, MLHO argued that since a TPMS malfunction 
does not constitute an emergency, the malfunction need not to be 
detected prior to vehicle movement.
    Instead, MLHO recommended that the proposed detection requirements 
in S4.2 of the NPRM should be revised to require the TPMS to detect the 
significantly under-inflated tire(s) and to illuminate the low tire 
pressure telltale within 10 minutes after the vehicle is in motion 
within the standard's designated speed range. MLHO requested that NHTSA 
also include language in S4.2 to specify that the TPMS will not be 
expected to either illuminate or extinguish the low tire pressure 
telltale without the vehicle being in motion, as motion is necessary 
for some systems to assess the vehicle's tire pressure status.
    MLHO stated that as currently proposed, the NPRM imposes 
unnecessary design restrictions, favors the ``present dominant RF-based 
technology,'' and discriminates against small businesses.
    NHTSA has carefully considered the commenters' countervailing 
arguments regarding the time limit for the TPMS to detect a 
significantly under-inflated tire, and we have decided to modify the 
relevant requirement in this final rule. As revised, under S4.2 of the 
standard, the TPMS must illuminate a low tire pressure warning telltale 
not more than 20 minutes after the inflation pressure in one or more of 
the vehicle's tires, up to a total of four tires, is equal to or less

[[Page 18148]]

than the pressure 25 percent below the vehicle manufacturer's 
recommended cold inflation pressure or the pressure specified in the 
3rd column of Table 1 of this standard for the corresponding tire type, 
whichever is higher. We believe that this detection time period is 
appropriate for the following reasons.
    As noted in the agency's June 5, 2002 Federal Register notice, 
TPMSs were not developed to warn the driver of extremely rapid pressure 
losses that could accompany a vehicle encounter with a road hazard or a 
tire blowout.\24\ According to the tire industry, those types of events 
account for approximately 15 percent of pressure loss cases.\25\ 
Arguably, a driver would be well aware of the tire problem in those 
situations, and the TPMS would provide little added benefit. Instead, 
TPMSs' benefits lie in warning drivers when the pressure in the 
vehicle's tires is approaching a level at which permanent tire damage 
could be sustained as a result of heat buildup and tire failure is 
possible; this low level of inflation pressure generally results from a 
more measured pressure loss (produced over weeks or months) caused by a 
slow leak, defective valve, or diffusion. According to the tire 
industry, approximately 85 percent of all tire pressure losses are slow 
air losses that occur over hours, weeks, or months of vehicle use.\26\ 
In those cases, a detection time of 20 minutes is not likely to pose a 
safety risk to the driving public.
---------------------------------------------------------------------------

    \24\ 67 FR 38704, 38728 (June 5, 2002).
    \25\ Id.
    \26\ Id.
---------------------------------------------------------------------------

    The agency's tire research suggests that even in a 25-percent 
under-inflated condition, the vehicle can be operated safely for this 
detection period without an appreciable risk of tire failure. 
Specifically and as noted above, NHTSA conducted testing on a variety 
of Standard Load P-metric tires at 20 psi with 100-percent load at 75 
mph for 90 minutes on a dynamometer, and none of these tires 
failed.\27\ This testing led the agency to conclude that warnings at 
less severe conditions will give drivers sufficient time to check and 
re-inflate their vehicles' tires before the tires experience 
appreciable damage. Commenters advocating a reduced detection time did 
not provide any evidence to demonstrate that operation of the vehicle 
with one or more tires under-inflated by 25 percent leads to tire 
damage or tire failure. Although manufacturers are encouraged to 
provide the low tire pressure warning as quickly as possible, we 
believe that a 20-minute detection period is unlikely to result in any 
adverse safety consequences.
---------------------------------------------------------------------------

    \27\ Id. at 38726.
---------------------------------------------------------------------------

    We further believe that a change in the detection time is necessary 
in order to articulate a standard that is practicable and technology-
neutral. According to manufacturers' comments, even direct TPMSs will 
require additional time to detect and verify low tire pressure, in part 
as a result of FCC regulations limiting the frequency of electronic 
transmissions.
    Furthermore, we anticipate that the extended time period also will 
ease compliance for indirect systems (particularly when detecting 
multiple under-inflated tires). Most indirect and hybrid TPMSs cannot 
currently meet the four-tire, 25-percent under-inflation detection 
threshold within 20 minutes. However, we are aware of at least one 
indirect TPMS that is currently capable of doing so,\28\ and we expect 
that with additional time and effort, other indirect and hybrid systems 
also would be able to meet the requirements of the standard.
---------------------------------------------------------------------------

    \28\ Docket No. NHTSA-2004-19054-96.
---------------------------------------------------------------------------

    In sum, without an extension of the time period for low tire 
pressure detection and warning, the number of TPMS technologies 
available for use under the standard may be significantly curtailed. 
Available information does not demonstrate a safety need for imposing 
such limitations, and we believe that drivers would operate the vehicle 
for 20-minutes periods with some frequency. For these reasons, we 
believe that a 20-minute detection time period is both practicable and 
meets the need for motor vehicle safety.
    We have decided not to extend the low tire pressure detection time 
beyond 20 minutes, however, as requested by some manufacturers in their 
comments. Available research shows that 75 percent of commuters 
regularly experience commute times of 30 minutes or less.\29\ A recent 
study by the U.S. Census Bureau, using 2002 survey data, found that 
average commute times for most major U.S. cities range from 20 to 30 
minutes.\30\ Many other trips, such as routine errands, may also 
involve drive times of less than 30 minutes. Therefore, if we were to 
require a low tire pressure detection time of 30 minutes or more, it is 
conceivable that consumers could be driving on significantly under-
inflated tires for a potentially extended period of time without 
receiving a warning from the TPMS.
---------------------------------------------------------------------------

    \29\ This statistic is based upon the results of a Washington 
Post-ABC News-Time poll conducted by telephone from January 27-31, 
2005 among 1,204 randomly selected adults nationwide. Results of 
this poll were reported in the Washington Post on February 13, 2005, 
at page A1.
    \30\ See http://www.census.gov/acs/www/Products/Ranking/2002/R04T160.htm.
---------------------------------------------------------------------------

    In addition, we are concerned that extending low pressure detection 
time period beyond 20 minutes could be problematic in other situations. 
For example, where a tire is punctured by a nail or is otherwise 
damaged and may experience a moderately rapid pressure loss. As to 
damaged tires but experiencing a relatively less rapid pressure loss, 
research into the rate of temperature buildup shows that for constant 
load, pressure, and speed conditions, tires generally warmed up and 
stabilized their temperatures within 15 minutes of testing;\31\ thus, 
the tire will rapidly reach a temperature that places stress on an 
under-inflated tire. In both of those cases, we are concerned that a 
30-minute detection time could delay the warning to the driver too 
long. For these reasons, we have decided that a requirement that would 
permit a low tire pressure detection time longer than 20 minutes could 
diminish the overall utility of the TPMS and concomitantly reduce the 
safety benefits associated with that system.
---------------------------------------------------------------------------

    \31\ See June 5, 2002 comments of the Rubber Manufacturers 
Association (Docket No. NHTSA-00-8011-64).
---------------------------------------------------------------------------

    In response to the concerns of MLHO, it was never the agency's 
intention to require detection absent vehicle motion. As demonstrated 
by the standard's test procedures, the detection time for low tire 
pressure includes a period of vehicle operation within a designated 
speed range (see S6(f)). This provision for vehicular motion is already 
built in to the general requirements of S4.1, which provides that the 
TPMS must meet the detection requirements of S4 under the test 
conditions specified in S5 and the test procedures specified in S6 of 
the standard. We believe that no further modifications to the standard 
are necessary related to this point.
2. TPMS Malfunction Indicator Lamp (MIL) Activation Requirements
    Paragraph S4.4 of the NPRM proposed to require each covered vehicle 
to be equipped with a TPMS that includes a telltale that illuminates 
whenever there is a malfunction that affects the generation or 
transmission of control or response signals in the TPMS and 
extinguishes when the malfunction has been corrected.
    The NPRM's proposed requirement for a TPMS Malfunction Indicator 
Lamp (MIL) was not included in earlier rounds of the TPMS rulemaking 
process. Consequently, the agency

[[Page 18149]]

expected and did receive extensive public comment on this proposed 
provision. Commenters offered recommendations regarding how quickly the 
TPMS must detect system malfunctions, the types of functions to be 
detected, and the test procedures for detecting such malfunctions. Each 
of these topics will be discussed in turn.
    (a) Time Period for Malfunction Detection. The NPRM did not specify 
a time period for the TPMS to detect a malfunction and to illuminate 
the TPMS MIL.
    The Association of International Automobile Manufacturers, Inc. 
(AIAM) expressed concern that the NPRM would require detection and 
notification of a TPMS malfunction immediately upon occurrence. 
However, AIAM stated that immediate detection is not possible in most 
cases, because TPMSs generally require the vehicle to be in motion in 
order to detect a malfunction (an argument also raised by Honda Motor 
Co., Ltd. and American Honda Motor Co., Inc. (Honda) and EnTire), and 
several transmissions from the pressure sensor to the controller are 
required to validate the existence of a malfunction.
    AIMA stated that the FCC requires a pause between signal 
transmissions at least 30 times as long as the signal transmission 
itself. In addition, AIMA stated that interference may result in the 
loss of some of these signals. AIMA argued that a requirement for 
immediate detection and reporting of a TPMS malfunction could result in 
many false positive warnings, which could undermine consumers' faith in 
the system and potentially lead them to ignore TPMS-related warnings 
(an argument repeated by General Motors North America (GM) and Hyundai 
in their comments). In light of the above, AIMA recommended that the 
agency allow the TPMS between 30 and 60 minutes to determine with a 
high degree of certainty whether a true malfunction is present (e.g., 
not one caused by signals external to the vehicle). The Alliance made a 
similar comment, suggesting a 30-minute detection time for a 
malfunction.
    Several other commenters also recommended that the agency specify a 
time period for the detection of a TPMS malfunction, although the 
recommended time periods varied. For example, ALPS Automotive, Inc. 
(ALPS) and Honda commented that a TPMS cannot detect malfunctions any 
faster than the system can detect low tire pressure and that the same 
durational parameters should be set for both functions. ALPS, BERU, 
Schrader Electronics, Ltd. (Schrader), and Fuji Heavy Industries USA, 
Inc. (Fuji) each recommended a 10-minute detection time. BERU stated 
that it does not support an ``excessive[ly] long'' duration for TPMS 
malfunction detection, because an extended ride (even 20 minutes) with 
a defective TPMS or an incompatible tire could prevent a low pressure 
warning and lead to a tire blow out. BERU also recommended 
specification of a vehicle moving distance. BERU stated that 
specifications for ``duration'' and ``vehicle moving distance'' are 
necessary not only for the detection of a malfunction, but also for the 
validation of the correction of a malfunction.
    EnTire and Hyundai recommended a malfunction detection time of 20 
minutes. According to EnTire, if a pressure sensor is disabled, it can 
take over 13.5 minutes for the fault to ``mature'' and to be detected 
by the system and suggested 20 minutes as a reasonable detection time. 
(EnTire also suggested 20 minutes as a reasonable extinguishment time 
for the MIL, and Fuji recommended that a vehicle be driven at least 10 
minutes at a minimum of 40 kph in order to verify that the malfunction 
has been eliminated.) Hyundai commented that current direct TPMSs are 
designed so that a failure is recognized only when the control unit 
does not receive data from the pressure sensor for three to four 
consecutive delivery cycles. Hyundai stated that current systems, 
therefore, require approximately 20 minutes to properly detect and 
verify TPMS malfunctions, a time period consistent with minimization of 
nuisance warnings.
    GM recommended a 30-minute drive time for TPMS malfunction 
detection. GM stated that the MILs for its current TPMSs have a 25-
minute drive period for the detection threshold, and the company is not 
aware of any consumer complaints arising from delayed TPMS malfunction 
warnings. GM argued that a TPMS that is programmed to be highly 
reactive in terms of malfunction detection and that provides an 
immediate response may result in relatively frequent malfunction 
warnings because common, everyday occurrences are likely to temporarily 
disturb the TPMS's signals.
    MLHO stated that the regulatory text related to the TPMS 
malfunction detection requirement should be revised to focus on the 
detection of a malfunction or correction of a malfunction, rather than 
the occurrence of those events. MLHO's comment is related to those 
about the need for the system to have adequate time to detection the 
presence or absence of a malfunction.
    DaimlerChrysler Corporation (DaimlerChrysler) made a general 
argument that NHTSA has not calculated or otherwise demonstrated any 
significant safety benefits associated with the TPMS MIL.
    Based upon the information provided by the commenters, we have 
decided to modify our approach to the MIL by providing a time period 
for malfunction detection and a speed range in which the vehicle will 
be driven as part of the malfunction detection phase in the test 
procedures. Specifically, this final rule requires the TPMS to detect a 
malfunction and to illuminate the MIL within 20 minutes of the 
occurrence of a malfunction, when the vehicle is driven at a speed 
between 50 km/h and 100 km/hr.
    Several commenters have stated that TPMSs generally require the 
same amount of time to detect and to verify a malfunction as they do 
for low tire pressure. As discussed above, the detection time period 
for low tire pressure has been increased to 20 minutes. A number of 
commenters stated that 20 minutes would provide adequate time for TPMS 
malfunction detection, with some commenters recommending an even 
shorter time period (e.g., 10 minutes). We also believe that specifying 
a time period for detection addresses MLHO's comment that the standard 
should not imply a requirement for automatic illumination of the MIL as 
soon as a malfunction occurs.
    We understand that certain TPMS technologies require vehicular 
motion in order to diagnose a TPMS malfunction, which is similar to the 
way in which such systems detect low tire pressure. For that reason, we 
are now specifying in the standard's test procedures that the vehicle 
will be driving within a designated speed range during the malfunction 
detection phase.
    We see important benefits in including a MIL requirement as part of 
the final rule. First, the malfunction detection requirement is 
intended to ensure the long-term functionality of the TPMS by 
identifying those small number of replacement tires with construction 
characteristics that would prevent proper operation of the TPMS. 
Without the TPMS MIL, some drivers would lose the benefit of the low 
tire pressure warning to be provided by the TPMS. The malfunction 
indicator was recommended by the Alliance as a solution to this 
problem. In addition, the MIL could provide ancillary benefits by 
alerting the driver of other situations where the system becomes non-
operational; in some cases, the problem may be temporary (e.g., brief 
signal

[[Page 18150]]

disturbance), but in other cases, the MIL may signal the need for 
repair of the TPMS. In all these cases, it is useful to the driver to 
be aware that the system is unavailable to provide a low tire pressure 
warning.
    However, with the above said, we do believe that the above 
accommodations can be made without any significant decrease in safety 
benefits. A TPMS malfunction does not itself represent a safety risk to 
vehicle occupants, and we expect that the chances of having a TPMS 
malfunction and a significantly under-inflated tire at the same time 
are unlikely. Even if that is the case, we do not believe that a 20-
minute detection time would increase occupant risk appreciably.
    (b) What Constitutes a TPMS Malfunction? The NPRM proposed to 
require the MIL to illuminate ``whenever there is a malfunction that 
affects the generation or transmission of control or response signals 
in the vehicle's tire pressure monitoring system'' and to extinguish 
when such malfunction is corrected (S4.4(a)).
    A number of commenters argued that proposed malfunction requirement 
is overly broad and in need of modification. The Alliance, the 
organization that originally suggested consideration of a TPMS MIL, 
stated that it remains committed to providing an in-vehicle indication 
when there is inadequate signal reception from one or more TPMS 
sensors. However, the Alliance stated that the technical specifications 
for the MIL proposed in the NPRM are different than the MILs that 
Alliance members were expecting and, in some cases, are inconsistent 
with the MILs that manufacturers are already voluntarily providing.
    Fuji stated that although it is reasonable to require malfunction 
detection for components that sense and transmit tire inflation 
pressure data, the standard should only require malfunction detection 
and warning in three situations: (1) When there is inadequate (or no) 
input signal from the wheel sensors; (2) when there is inadequate (or 
no) input signal from the antenna to the electronic control module 
(ECM), or (3) when there is inadequate (or no) input signal from other 
systems used by the malfunction warning system (e.g., ABS wheel speed 
input to the ECM). Fuji stated that malfunctions in the TPMS ECM (which 
contains the logic to determine that a malfunction exists) would be 
impossible to indicate via the MIL, because the module would not be 
functioning to operate the lamp.
    Sumitomo commented that paragraph S4.4, as proposed, should be 
modified to require the TPMS to indicate a malfunction under the 
following two conditions: (1) When wheel speed signals cannot be 
transmitted from wheel speed sensors to the TPMS, and (2) when tire 
pressure signals cannot be transmitted from the pressure sensors to the 
TPMS.
    ETV stated that the MIL should indicate the following malfunctions: 
(1) Incompatibility of replacement tires/rims; (2) sensor failure; (3) 
signal failure in communications channel; (4) reader electronics 
failure, and (5) telltale bulb failure. ETV argued that there should be 
a redundancy or failsafe built into the system so that a burnt out 
telltale bulb can still produce a malfunction warning, so as to alert 
the consumer that that bulb needs replacement.
    Hyundai stated that there are three types of TPMS malfunctions that 
will require addition of a separate electrical circuit to activate the 
MIL: (1) Disconnection of the power source to the main control unit; 
(2) disconnection of the power source to the telltale lamp, and (3) 
disconnection of wiring between the main control unit and the telltale 
lamp. Hyundai requested that the agency exclude these three 
malfunctions from the requirements of the standard during the phase-in 
period, because incorporating detection capabilities for these types of 
malfunctions would require additional development time. Alternatively, 
Hyundai suggested that detection of these conditions could be achieved 
through the bulb check function and supplemental language in the 
owner's manual; in those cases, the TPMS lamp would not be illuminated 
during the bulb check, and the driver would consult the owner's manual 
to be alerted to the TPMS malfunction in such cases.
    In addition, Hyundai stated that even though components such as the 
electronic control unit (ECU) or vehicle speed sensors are involved in 
TPMS operation, failure of these components should not be considered a 
TPMS malfunction. Mitsubishi stated that the MIL should not be required 
to provide a warning during brief interruption of communication between 
sensors and the ECU because the TPMS uses radio communications that can 
be affected by external interference; this is a common occurrence that 
could result in false positive warnings. GM made a similar point about 
not requiring the TPMS MIL to illuminate during brief and temporary 
interruption of signals.
    The comments of American Suzuki Motor Corporation (Suzuki) 
discussed the malfunction detection capabilities of the TPMS currently 
installed on the Suzuki XL-7. According to Suzuki, that system provides 
a malfunction indication when there is either a loss of power to the 
TPMS control unit or when there is no electrical connection between the 
control unit and the TPMS telltale. Suzuki stated that although its 
system is not compliant with the NPRM's proposed MIL requirements, it 
believes that its system is just as effective as the MIL technical 
specifications in the NPRM. Therefore, Suzuki requested that NHTSA 
adopt ``less design-restrictive'' requirements for the TPMS MIL, so as 
to allow continued use of its system.
    NIRA Dynamics commented that it is important to keep the 
malfunction indicator requirements generic, so that any TPMS technology 
may be used. As examples of limitations specific to certain types of 
TPMS technology, NIRA Dynamics stated that: (1) Many direct systems 
cannot detect a malfunction when the vehicle is stationary if the 
sensor does not have any contact with the receiver due to wheel angle; 
(2) it is impossible for indirect systems to detect a malfunction when 
the vehicle is stationary because the wheel must rotate to diagnose the 
sensor, and (3) indirect systems cannot detect tire incompatibilities. 
NIRA Dynamics urged that the final rule should simply require TPMSs to 
be designed to detect malfunctions ``according to good engineering 
practices.''
    Honda's comments sought confirmation that the following system 
failures would be excluded from the TPMS MIL activation and warning 
requirements: TPMS indicator light, TPMS coupler, and meter panel. 
Honda argued that it would be unnecessary for the TPMS MIL to report 
these failures because they would be apparent upon bulb check. Honda 
also requested that the agency issue a laboratory test procedure for 
generating a TPMS system fault, so as to clear up any confusion related 
to the types of malfunctions that will be subject to testing.
    Continental Teves, Inc. (Continental Teves) also commented that for 
a hybrid system, it would not be possible for the TPMS to illuminate 
the MIL to indicate an incompatible tire unless it is on a wheel with a 
pressure sensor. Continental Teves stated that the TPMS MIL should not 
be required to illuminate when an incompatible replacement tire is 
installed, but instead, the system should be permitted to continue to 
function with reduced performance without the MIL being lit. BMW also 
stated that the TPMS MIL should not be required to illuminate when 
system failure is the result of a change to an incompatible tire, 
because

[[Page 18151]]

such failure is not the result of a malfunction of the TPMS.
    Schrader commented that the TPMS should not be required to signal a 
malfunction when the ignition locking system is in the lamp-check 
position, because that status check should be reserved for confirming 
the functionality of the telltale bulb.
    After careful consideration of the public comments, we have decided 
to retain the NPRM's requirement for the MIL to illuminate whenever 
there is a malfunction that affects the generation or transmission of 
control or response signals in the vehicle's tire pressure monitoring 
system. Although the commenters expressed preferences for TPMSs with 
reduced malfunction detection capabilities, they did not state that it 
would be impracticable to provide the proposed warnings. Furthermore, 
we believe that, given adequate lead time, this requirement is 
practicable, because a nearly identical malfunction requirement for 
anti-lock braking systems (ABS) is contained in FMVSS No. 121, Air 
Brake Systems, and vehicle manufacturers have certified to that 
standard successfully. We expect that manufacturers would similarly be 
able to meet the malfunction detection requirements of the TPMS 
standard.
    As drafted, the TPMS malfunction detection requirement is 
technology-neutral and capable of accommodating system design changes 
without the need to continually amend the standard. For example, in a 
direct TPMS, the control signals are generated by the wheel sensor and 
transmitted to an electronic control unit via an antenna. In contrast, 
in an indirect TPMS, the control signals may be generated by the ABS 
wheel sensor and transmitted to the electronic control unit directly. 
The present requirement encompasses both types of systems.
    In response to comments suggesting that the TPMS MIL should only 
detect specific malfunctions, the agency believes that such 
restrictions would unnecessarily reduce the safety benefits of the 
TPMS. Specifications in the standard that would limit malfunctions that 
must be detected could impose design restrictions on manufacturers 
because such specifications and the components to which they refer may 
not be applicable to current or future TPMS designs. The agency 
recognizes that the requirement for malfunction detection includes all 
TPMS components and may require some additional circuitry and software, 
but we believe that with minor modifications, it would be practicable 
to monitor all TPMS components for malfunction. Therefore, we are not 
adopting the specific limitations recommended by the commenters.
    We agree with the comment of Schrader that the MIL should not be 
required to signal a burned out bulb as a TPMS malfunction, because 
that problem would already be identified during the check-of-lamp 
function at vehicle start-up.
    As discussed previously, we recognize that most TPMSs require 
vehicular motion in order to detect a system malfunction, so we have 
incorporated a 20-minute drive time in a designated speed range as part 
of the standard's test procedures for malfunction detection.
    We do not agree with the comments stating that the MIL should not 
be required to illuminate during periods of brief external signal 
disturbance. The TPMS is unlikely to know for how long a signal 
disturbance will continue. Instead, we believe that the driver should 
be provided a warning that the TPMS system is unavailable to detect low 
tire pressure. This situation is not a false positive, but instead, it 
involves a period when the TPMS is unavailable, although through no 
fault of its own. Once the period of signal disturbance passes, the 
TPMS should detect that the problem has been resolved and extinguish 
the MIL, and no additional action on the part of the driver would be 
required.
    In addition, during periods of brief disturbance, the TPMS's 
circuitry and software may require time to detect a malfunction, and 
the MIL telltale may ultimately not illuminate. As discussed above, we 
are requiring the TPMS to detect a malfunction and to illuminate the 
TPMS MIL within 20 minutes of the occurrence of such malfunction. This 
time period for detection should provide the system with an adequate 
opportunity to determine whether the disturbance is, in fact, brief 
before illuminating the MIL.
    We also disagree with commenters who suggested that the TPMS MIL 
should not be required to signal when the vehicle is equipped with 
alternate or replacement tires that prevent continued proper 
functioning of the TPMS. That requirement is key to the long-term 
functionality of the TPMS, and unless such a warning is provided, some 
drivers may lose the benefits of the system entirely. It is plainly 
foreseeable that most vehicles will outlast their original set of 
tires, so this requirement is necessary to ensure that consumers 
continue to receive the TPMS's important information related to low 
tire pressure.
    In response to Honda's comment that the agency should rapidly issue 
a laboratory test procedure for generating a TPMS system malfunction, 
we would offer the following clarification and cautionary note. It is 
our intention to publish guidelines to test facilities that the agency 
contracts with to conduct compliance testing in the near future. These 
guidelines are referred to as compliance test procedures, and they are 
intended to provide a standardized testing and data recording format 
among the various contractors that perform testing on behalf of the 
agency, so that the test results will reflect performance 
characteristics of the product being tested, not differences between 
the various testing facilities. However, we would stress that vehicle 
manufacturers' certification responsibilities are linked to the 
requirements, test procedures, and test conditions articulated in the 
standard, not the laboratory test procedures.
    (c) MIL Disablement. The NPRM did not contain any provision for MIL 
disablement.
    Honda requested clarification as to whether it would be permissible 
to disable or to suppress the MIL when the TPMS sending units have been 
removed as a result of the replacement of the original equipment tires 
and rims with aftermarket components that are not compatible with the 
direct-sensing TPMS. Honda stated that it had previously received 
complaints from customers and dealers who encountered this situation 
and were confronted with a recurrent malfunction warning. The company 
expressed concern that if the MIL cannot be suppressed in these 
situations, consumers may become desensitized to MILs generally, which 
could have negative implications for occupant safety. NADA provided a 
similar comment.
    We do not believe it is appropriate to permit disablement of the 
MIL when aftermarket tires and rims are installed on the vehicle that 
are not compatible with the continued proper functioning of the TPMS. 
In such cases, the TPMS MIL is performing its intended function. We 
believe that the MIL should continue to operate when tires and rims 
that are incompatible with the TPMS are mounted on the vehicle, not 
only to discourage such actions, but also to provide an ongoing 
reminder that the TPMS is unavailable to provide low tire pressure 
warnings.
3. Telltale Requirements
    The NPRM proposed to require installation of either a single TPMS 
telltale (i.e., a combination telltale indicating both low tire 
pressure and system malfunction) or separate telltales

[[Page 18152]]

for low tire pressure and malfunction indication.
    For the low tire pressure warning, paragraph S4.3 of the NPRM 
proposed to require a telltale that is mounted inside the occupant 
compartment in front of and in clear view of the driver, which is 
identified by one of the symbols for ``Low Tire Pressure Telltale'' in 
Table 2 of FMVSS No. 101, Controls and Displays, and is illuminated 
under the conditions specified in S4.2. For low tire pressure telltales 
that identify which tire(s) is (are) under-inflated, the NPRM proposed 
to require that each tire in that symbol must illuminate when the tire 
it represents is under-inflated to the extent specified in S4.2. That 
paragraph also proposed to require the low tire pressure telltale to 
illuminate during a check-of-lamp function, and stated that the 
telltale would not be required to illuminate when a starter interlock 
is in operation.
    For the TPMS MIL, paragraph S4.4 of the NPRM proposed two options 
for compliance. As the first option, under S4.4(b), a vehicle 
manufacturer could install a dedicated TPMS malfunction telltale that 
is mounted inside the occupant compartment in front of and in clear 
view of the driver, which is identified by one of the symbols for 
``TPMS Malfunction Telltale'' in Table 2 of FMVSS No. 101, and is 
continuously illuminated under the conditions specified in S4.4(a). 
That paragraph also proposed to require the MIL to illuminate during a 
check-of-lamp function, and stated that the telltale would not be 
required to illuminate when a starter interlock is in operation.
    As the second option, under S4.4(c), a vehicle manufacturer could 
install a combined Low Tire Pressure/TPMS Malfunction telltale that 
continues to meet the low tire pressure detection requirements of S4.2 
and S4.3 and meets the MIL requirements of S4.4(a) in the following 
fashion. The NPRM proposed to require the combined telltale to flash 
for one minute upon detection of any malfunction condition specified in 
S4.4(a) after the ignition locking system is turned to the ``On'' 
(``Run'') position. After the first minute, the telltale would be 
required to remain continuously illuminated as long as the malfunction 
exists and the ignition locking system is in the ``On'' (``Run'') 
position. The NPRM proposed that this flashing and illumination 
sequence would be required to be repeated upon subsequent vehicle 
start-ups until the situation causing the malfunction has been 
corrected, after which time the telltale must extinguish.
    (a) Function and Format of the Combined Low Pressure Warning/
Malfunction Indicator Lamp.
    A number of commenters discussed the issue of how the MIL would 
operate, particularly when it is combined with the low pressure warning 
telltale. No consensus was evident, as reflected by the variety of 
viewpoints in the following discussion of comments.
    Some commenters argued that the proposed requirements for the TPMS 
MIL are design-restrictive and may impose unnecessary costs. In its 
comments, AIAM opposed the use of a flashing low pressure telltale to 
indicate TPMS malfunction when the MIL is part of a combined format, 
because such a format may require significant software and hardware 
changes. AIAM stated that a separate MIL will not be feasible for many 
vehicles, and that the NPRM's limited MIL design options would restrict 
a number of potentially innovative solutions (e.g., voice malfunction 
indicators, other visual or text messaging displays).
    AIAM argued that NHTSA instead should include a technology-neutral 
requirement for a MIL, but leave MIL design to the discretion of the 
vehicle manufacturer. Porsche Cars North America, Inc. (Porsche) argued 
that there is no evidence that clear and concise text messages create 
confusion, and the company recommended that the final rule permit text 
messages related to TPMS malfunction and permit those messages to be 
cleared by the driver (but not permit clearing of the low pressure 
telltale). The Alliance, BMW, DaimlerChrysler, and VW/Audi all 
expressed similar views regarding allowing design freedom for MILs with 
a mix of product offerings. Suzuki suggested that manufacturers should 
be permitted to explain how different malfunctions are identified in 
the vehicle owner's manual.
    DaimlerChrysler stated that its experience has shown TPMS 
malfunctions to be uncommon events, and therefore, detailed MIL 
specifications are not warranted because they do not address a 
significant safety problem or provide a significant safety benefit. 
DaimlerChrysler argued that it should be sufficient to have the final 
rule that the malfunction indicator ``be present, visible to the 
driver, perceptually upright, and explained in the owner's manual.''
    Others were concerned that the flashing-to-steady-burning MIL could 
lead to consumer confusion. The Alliance questioned whether having the 
combined telltale flash for one minute and then become steady burning 
to indicate a malfunction would confuse consumers as to whether a 
malfunction or a low tire pressure condition exists. More specifically, 
Hyundai stated that the initial one-minute flashing sequence may be an 
insufficient period of time, because, particularly at vehicle start-up, 
the driver may be preoccupied with other tasks and may not notice the 
flashing telltale until it becomes steady-burning, at which time it may 
be misconstrued to be a low pressure warning (a similar comment was 
provided by Emtop). Hyundai recommended that NHTSA either consider 
other alternatives (e.g., periodic flashing) or an extension of the 
one-minute time period for the initial flashing. The comments of 
Mitsubishi Motors R&D of America, Inc. (Mitsubishi) and the TIA shared 
this view. DaimlerChrysler, Mitsubishi, and Nissan North America, Inc. 
(Nissan) went even further in their comments and suggested a 
continuously flashing TPMS MIL, which would be distinct from the 
continuous warning for low tire pressure.
    TIA also expressed concern that even if the driver does notice the 
initial flashing sequence of the combined TPMS telltale, that person 
still may not comprehend its significance, instead misconstruing it as 
part of normal vehicle start-up. According to TIA, if that were the 
case, even a more detailed explanation in the owner's manual would be 
insufficient because the driver may never realize the need to consult 
it. TIA also commented that a separate TPMS MIL telltale would add yet 
another light to an already crowded dashboard. (BMW and Porsche 
provided similar comments.) BMW commented that a combined telltale 
would preserve space for future safety-related technologies and 
warnings.
    Porsche argued that the 60-second flashing format for the proposed 
combined telltale is unwarranted and a potentially dangerous way to 
signal a TPMS malfunction. According to Porsche, a flashing telltale 
would send an incorrect message to the driver that something is 
seriously wrong with the vehicle, potentially alarming the driver and 
leading to a panic situation that could distract the driver's attention 
from driving.
    In contrast, Emtop argued that there is not any evidence to suggest 
that flashing telltales produce inappropriate driver responses or that 
the intended messages are misunderstood, unless the indication is 
inconsistent.
    Fuji's comments suggested that the form of the MIL warning should 
depend upon the type of malfunction encountered. More specifically, 
Fuji stated that malfunctions in the TPMS

[[Page 18153]]

ECM (which contains the logic to determine that a malfunction exists) 
would be impossible to indicate via the MIL, because the module would 
not be functioning to operate the lamp. Fuji recommended that the MIL 
should flash as long as the malfunction exists in components 
``downstream'' of the ECM (e.g., loss of signal from a wheel sensor) 
but that the MIL should have continuous illumination for malfunctions 
of components ``upstream'' of the ECM (e.g., wiring harness to 
telltale, loss of power to the ECM). Fuji stated that this hierarchy 
would not apply to situations where the TPMS failed the bulb check.
    NADA stated that the TPMS could use a single warning lamp to 
indicate a variety of conditions (i.e., low tire pressure, incompatible 
tires, TPMS malfunction). Under the approach recommended by NADA, when 
the telltale is illuminated, the owner would consult (at least the 
first time) the following decision tree provided in the vehicle owner's 
manual in order to determine the meaning of that illumination: (1) 
There is an inflation concern. Check tire pressures. If okay, proceed 
to (2); (2) A tire is incapable of being monitored. Check tires. If 
okay, proceed to (3); (3) The system is faulty. See your motor vehicle 
dealer. NADA stated that the final rule should include a requirement 
for owner's manual language consistent with its recommended approach.
    Emtop commented that having separate TPMS telltales for low tire 
pressure and the malfunction indicator is inadvisable because an 
additional telltale is costly, would consume limited display space, and 
would provide little or no additional safety benefit. In contrast to 
earlier commenters, Emtop argued that having separate telltales would 
confuse drivers and undermine confidence in the TPMS, and it also 
argued that allowing a choice in format could further confuse consumers 
who drive multiple vehicles when they encounter systems with different 
indicators.
    In addition, Emtop recommended reversing the NPRM's approach to the 
low pressure and MIL warning signals, urging the agency to require the 
telltale to flash to indicate low tire pressure and to be continuously 
illuminated to indicate a TPMS malfunction. According to Emtop, a 
flashing telltale is more likely to be noticed and implies a potential 
danger, so in this case, Emtop recommended requiring the telltale to 
flash continuously to indicate low tire pressure, a potentially serious 
condition which is relatively easy for the driver to correct. (Honda 
provided a similar comment.) Emtop also recommended this approach 
because a flashing malfunction indicator would require a control signal 
that may be unable to produce the requisite flashing if the malfunction 
affects the control signal itself; according to Emtop, indicating a 
malfunction in a steady state would be more appropriate because an 
indicator can be made to default to a fixed state in the absence of a 
control signal.
    In its comments, Emtop also questioned the message conveyed by a 
flashing-to-steady MIL, which it argued may be confusing, counter-
intuitive, and context dependent. According to Emtop, drivers may 
equate a change in the indicator with a change in condition. Emtop also 
suggested that the messages in a combined telltale could be confused in 
situations where low tire pressure is masked by the malfunction warning 
or where a low pressure warning flickers (e.g., due to fluctuating 
pressure causing the light to turn on and off), problems which may 
increase as future TPMS technology reduces system reaction time.
    Emtop recommended specifying a flash rate of one to three times per 
second, noting that the flash rate could be changed to convey a greater 
sense of urgency to the driver if the situation deteriorates without 
being remedied. Emtop stated that its TPMSs already have a progressive 
flash rate that has been tested and well received by consumers. (EnTire 
and Honda also recommended specification of a flash rate for the 60-
second flashing malfunction indication, as well as a tolerance for the 
60-second period. EnTire recommended a tolerance for the 60-second 
period of  10 seconds, whereas Honda recommended a 
tolerance of  5 seconds.)
    Public Citizen urged the agency to mandate separate warning 
indicators for low tire pressure and TPMS malfunction because a 
combined telltale could be confusing, particularly for older drivers 
who may have poorer vision and slower reaction times. (Advocates 
provided a similar comment.) Public Citizen argued that both warning 
telltales should be required to flash until the underlying problem is 
corrected. The organization stated that flashing telltales convey a 
sense of urgency and are more likely to elicit a driver response, and 
it suggested that a flashing indicator could be programmed to provide 
additional information, such as by flashing more frequently at 
increasingly lower pressure levels. Public Citizen argued that the 
agency has provided no support for a determination that flashing 
telltales are a nuisance or otherwise unacceptable.
    BERU requested clarification of whether the MIL should be 
illuminated while the system is running validation protocols to 
determine whether a problem has been corrected. (Presumably, this 
question applies to both combined and separate TPMS MILs.)
    EnTire sought clarification as to whether vehicles that are 
equipped with both of the proposed low tire pressure telltales (i.e., 
the single symbol and the symbol showing individual tires) are required 
to have both symbols indicate a TPMS malfunction per the defined 
procedure or whether the MIL may be incorporated in only one of those 
telltales.
    After considering the public comments and all available 
information, we have decided to retain the NPRM's general approach to 
the telltale requirements for both the low tire pressure warning and 
the TPMS malfunction indicator (with minor modifications), because we 
believe that this approach provides an effective message to virtually 
all drivers. As part of this final rule, we have decided to permit use 
of either separate telltales for the low tire pressure warning and the 
TPMS malfunction indicator, or a combined telltale that incorporates 
both functions. We believe that a visual telltale is necessary to 
provide a clear and consistent message to the driver. We do not believe 
that other suggested alternatives (e.g., audible or text messages) 
would be as effective in providing those warnings. Furthermore, we are 
concerned that leaving the MIL to manufacturer discretion could result 
in a proliferation of warnings that may not be sufficiently noticeable 
or understandable to drivers. We believe that these warnings are 
extremely important in terms of providing tire pressure information to 
drivers or of alerting drivers when the systems is not available to 
provide such information. However, manufacturers may supplement the 
required warnings with these additional messages.
    The agency's cost-benefit analysis does not support a mandatory 
requirement for separate telltales, and we acknowledge that with 
limited space available on the dashboard, a combined telltale has the 
potential to preserve precious space for future safety warnings. 
However, we believe that there is sufficient justification for separate 
warnings to warrant permitting manufacturers to use separate warning 
telltales if they elect to do so. We believe that providing these two 
different compliance options offers

[[Page 18154]]

manufacturers greater flexibility in terms of their designs without 
sacrificing the important safety messages related to the TPMS.
    If the manufacturer chooses the option for separate telltales, the 
final rule requires a low tire pressure telltale that is mounted inside 
the occupant compartment in front of and in clear view of the driver, 
which is identified by one of the symbols for ``Low Tire Pressure 
Telltale'' in Table 2 of FMVSS No. 101, and is illuminated under the 
conditions specified in S4.2. For low tire pressure telltales that 
identify which tire(s) is (are) under-inflated, the final rule requires 
that each tire in that symbol must illuminate when the tire it 
represents is under-inflated to the extent specified in S4.2. That 
paragraph also requires the low tire pressure telltale to illuminate 
during a check-of-lamp function, and states that the telltale is not 
required to illuminate when a starter interlock is in operation.
    For the dedicated MIL, under S4.4(b), the final rule requires the 
vehicle manufacturer to install a TPMS malfunction telltale that is 
mounted inside the occupant compartment in front of and in clear view 
of the driver, which is identified by the word ``TPMS,'' as described 
under TPMS Malfunction Telltale'' in Table 2 of FMVSS No. 101, and is 
continuously illuminated under the conditions specified in S4.4(a). 
That paragraph also requires the MIL to illuminate during a check-of-
lamp function, and states that the telltale is not required to 
illuminate when a starter interlock is in operation.
    For the combined low tire pressure warning/MIL option, the final 
rule requires that the telltale must meet the low tire pressure 
detection requirements of S4.2 and S4.3 and also meet the MIL 
requirements of S4.4(a) in the following fashion. Upon detection of any 
condition specified in S4.4(a) after the ignition locking system is 
turned to the ``On'' (``Run'') position, the combined telltale must 
flash for a period of 60-90 seconds, after which, the telltale is 
required to remain continuously illuminated as long as the malfunction 
exists and the ignition locking system is in the ``On'' (``Run'') 
position. This flashing and illumination sequence must be repeated upon 
subsequent vehicle start-ups until the situation causing the 
malfunction has been corrected, after which time the telltale must 
extinguish.
    The final rule's requirement for a 60-90 second time period of 
flashing of the combined telltale to indicate a TPMS malfunction 
represents an increase from the NPRM's proposed requirement. We agree 
with comments that drivers may be distracted by other tasks at vehicle 
start-up and in some cases may miss a 60-second flashing sequence.\32\ 
However, we remain concerned that drivers may consider a lengthy or 
indefinite flashing sequence to be a nuisance, which could cause the 
driver to ignore the safety message. We are also concerned that the 
flashing telltale should elicit the appropriate driver response. Thus, 
the final rule's time period for flashing the combined telltale 
represents the agency's determination as how to best balance these 
competing concerns. We do not believe that it is necessary to specify a 
flash rate for the combined telltale, so we leave this matter to the 
discretion of the vehicle manufacturer.
    Although certain commenters objected to the manner in which the low 
tire pressure and MIL warnings are to be provided, those commenters did 
not provide any evidence to show that the agency's approach would 
confuse consumers or that their suggested alternatives would be more 
effective. The following explains our reasoning in not adopting these 
suggestions.
---------------------------------------------------------------------------

    \32\ We note, however, that in those cases where the driver does 
not see the flashing sequence, the anticipated response would be to 
check and inflate the vehicle's tires. Even if none of the vehicle's 
tires is ``significantly under-inflated,'' the outcome would be to 
return the tires to optimal pressure. This outcome would 
nevertheless be beneficial, although the driver may experience some 
consternation at the continued illlumination of the telltale. In 
addition, we do not expect that the driver would miss the MIL's 
flashing sequence on a regular basis.
---------------------------------------------------------------------------

    The TPMS standard represents a novel case in terms of the agency's 
use of a telltale. Prior to this final rule, NHTSA has not required a 
flashing telltale for any of the safety systems in any FMVSS. Although 
we agree with commenters that a flashing telltale is likely to attract 
driver attention more quickly than a continuously illuminated telltale, 
we also must consider the appropriateness of the driver's response to 
the warning.
    As we have discussed at various points in the course of this 
rulemaking, we do not believe that the TPMS's illumination of the low 
tire pressure telltale represents an urgent situation requiring 
immediate correction. As noted above, the agency's tire testing has 
shown that the vehicle can be operated safely with a tire that is 
under-inflated by 25 percent without an appreciable risk of tire 
failure for some reasonable period of time (i.e., at least 90 minutes). 
If a significantly under-inflated tire does not constitute an urgent 
situation, a TPMS malfunction is even less likely to represent an 
emergency situation requiring immediate driver attention. Thus, in the 
situations that would generate a TPMS-related warning, the desired 
response would not be to have the driver immediately pull over to the 
side of busy highway. That is the primary reason why the color yellow 
was selected for the TPMS telltale(s), rather than red. It is also the 
reason why we have chosen to require continuous illumination of the 
dedicated TPMS MIL and to require a limited period of flashing followed 
by continuous illumination (rather than continuous flashing) of the 
combined TPMS telltale. Particularly when combined with the color 
yellow, we do not see any reason to believe that a flashing TPMS MIL 
telltale, in and of itself, would produce a panic response on the part 
of the driver. Furthermore, we do not believe it is necessary to 
require the combined telltale to produce periodic flashing more 
frequent than upon subsequent vehicle start-ups.
    Some commenters suggested reversing the way the warning messages 
are presented in a combined telltale (i.e., requiring flashing to 
indicate low tire pressure and continuous illumination to indicate TPMS 
malfunction). While these arguments are not illogical, we have decided 
that it is appropriate, in this regard, to retain the approach proposed 
in the NPRM. We believe that drivers are likely to encounter the low 
tire pressure warning much more frequently than the malfunction 
warning. Thus, we believe that this situation should be assigned the 
continuous illumination format, which represents the norm. The 
presumably less frequent TPMS malfunction warning is being assigned the 
flashing-to-continuous illumination format. Although it is arguably 
true that the low pressure situation would be easier for the driver to 
correct, we believe that the final rule's approach would minimize the 
amount of flashing encountered by the driver overall.
    We believe that the messages presented by the different compliance 
options for the TPMS telltale(s) will be clear and apparent to most 
drivers. However, if any confusion arises, the first time the warning 
is encountered, the driver would be expected to consult the owner's 
manual to clarify the matter.
    We are not adopting NADA's recommendation to have a single TPMS 
telltale that would require the driver to run through a hierarchy of 
diagnostics to determine what type of problem is causing the telltale 
to illuminate. We envision significant driver frustration with such an 
approach, particularly in those cases where the telltale remains 
illuminated after pressure check and

[[Page 18155]]

correction. This scenario can be avoided by setting a performance 
requirement that differentiates between low tire pressure situations 
and TPMS malfunctions.
    In response to BERU's request for clarification, we note that the 
final rule requires the TPMS MIL to remain illuminated until such time 
as the condition causing the malfunction has been corrected. 
Accordingly, the MIL must remain illuminated while the system is 
running any validation protocols to determine whether the problem has 
been resolved, as the telltale is permitted to extinguish only after 
the TPMS can confirm that the system is again fully operational.
    In response to EnTire's question, if the vehicle manufacturer 
elects to incorporate both of the TPMS low tire pressure telltales, it 
is only necessary to include a malfunction indicator in one of those 
telltales. Requiring both telltales to indicate a malfunction would not 
only be redundant, but it would also unnecessarily increase the amount 
of flashing experienced by the driver. We leave it to the 
manufacturer's discretion to choose in which of the two telltales the 
MIL should be incorporated.
    Regarding Fuji's comment that the MIL should flash in certain 
circumstances and be continuously illuminated in other circumstances 
(depending upon the type of malfunction), we have decided not to adopt 
that recommendation. We are concerned that having different types of 
malfunction warnings within the same system could lead to consumer 
confusion. In order to detect malfunctions in all TPMS components, some 
additional circuitry and software logic may be required, as compared to 
current designs. We recognize that a failure of the control unit would 
be difficult to detect without appropriate circuitry and logic. 
Nevertheless, we believe that such a requirement for a flashing MIL 
would be practicable and achievable for all types of malfunctions.
    (b) Telltale Symbols for Low Pressure Warning and Malfunction 
Indication. Several commenters stated that the proposed symbols for low 
tire pressure and TPMS malfunction are difficult to distinguish and, 
therefore, potentially confusing. Emtop argued that to the extent that 
the symbols are confused, drivers may delay taking the appropriate 
remedial action, and it further stated that misunderstood telltales 
could undermine confidence in the TPMS.
    In its comments, the Alliance challenged statements in the NPRM 
indicating that the proposed symbol for the TPMS MIL could be 
recognized by consumers or that it would help achieve the desired 
response. The Alliance argued that the TPMS Docket does not provide 
documentation of the agency's evaluation of possible icons or the 
results of any focus group evaluation or study of such icons. The 
Alliance also stated that the proposed MIL icon is not consistent with 
the approach to other ISO standards, which indicate malfunctions by 
adding an exclamation point symbol (``!''). Accordingly, the Alliance 
argued that, in this instance, the MIL would require the addition of 
another exclamation point (``!'') on the side of the low tire pressure 
symbol. The Alliance commented that it is not aware of any ISO symbol 
attributing a meaning to the dashed element found in the NPRM's 
proposed TPMS MIL symbol, and instead, it suggested an alternate symbol 
(i.e., the low tire pressure icon with the capital letters ``TPM'' in 
the middle).
    Honda also recommended modifying the proposed TPMS malfunction 
warning telltale. Honda stated that the proposed malfunction symbol is 
new and not an internationally recognized symbol for TPMS malfunction, 
so Honda argued that there is latitude for a change. It recommended 
using the word ``TPMS'' for the system malfunction telltale. (Hyundai 
provided a similar comment.)
    VW/Audi suggested that for the malfunction indicator, a more 
meaningful TPMS malfunction symbol might utilize the low tire symbol 
with a diagonal bar across it, a feature that is generally interpreted 
as the negative of the underlying symbol.
    ETV expressed support for the proposed TPMS telltale that has the 
outline of a car with lighted indicators at each tire that can provide 
tire-specific information by referencing its installed location. ETV 
commented that, as opposed to the proposed ISO telltale design (which 
ETV referred to as the ``cutaway tire''), the alternate symbol provides 
a ``common sense'' and readily recognizable symbol for low tire 
pressure, which would leave the car symbol's roof area available for 
the TPMS malfunction signal. ETV urged NHTSA to require that the visual 
telltale be supplemented with an audible alarm.
    Advocates stated that the final rule should only permit the low 
tire pressure telltale that is capable of alerting the driver as to 
which tire is under-inflated, because motorists may not respond 
appropriately to re-inflate their tires unless they can tell which 
tire(s) is (are) under-inflated. Advocates argued that NHTSA has not 
provided any data regarding how consumers will react to a warning 
telltale that does not indicate which tire is under-inflated.
    In the final rule, we have decided to adopt the NPRM's symbols for 
low tire pressure, but we have decided to change the requirement for 
the MIL symbol. For the low tire pressure warning, an internationally 
recognized symbol has been developed by ISO, and we are adopting that 
symbol as one of the options under FMVSS No. 101. In addition, we are 
providing an option for a telltale with a car symbol that would allow 
the TPMS to indicate which tire(s) is (are) significantly under-
inflated by illuminating the corresponding tire on the telltale, which 
we believe would be readily understandable and also provide additional 
useful information to the driver. These symbols may be supplemented by 
the words ``Low Tire.''
    We are not expressing any preference between these two symbols. Not 
all TPMSs may be able to distinguish and identify which tire is 
significantly under-inflated, and we expected that if the low tire 
pressure telltale were to illuminate, most drivers would check and 
adjust the pressure in all of their tires. Further, the Advocates did 
not provide any data to demonstrate that the consumers would be 
confused by ISO's international symbol for low tire pressure. 
Therefore, in order maintain a technology-neutral standard, we are 
adopting the NPRM's two options for the TPMS low tire pressure symbol.
    Regarding the symbol for the TPMS malfunction indicator using a 
separate telltale, we have decided to modify the requirements proposed 
in the NPRM. (For those systems providing a combined low tire pressure/
TPMS malfunction warning in a single telltale, no additional symbol is 
required because malfunction is indicated by the flashing sequence 
discussed above.) Several commenters stated that the ISO symbol for low 
tire pressure and NHTSA's proposed symbol for the MIL were so similar 
as to be confusing. In addition, as noted by Honda and Emtop, there is 
not any internationally recognized symbol for TPMS malfunction, so the 
agency has latitude in selecting an appropriate symbol for the MIL.
    We agree that the TPMS-related telltales should be sufficiently 
distinct and comprehensible, so as to facilitate proper driver response 
in both low tire pressure and TPMS malfunction situations. Accordingly, 
consistent with the recommendations of Honda and Hyundai in their 
comments, we have decided that for dedicated TPMS malfunction 
telltales, the telltale must display the word ``TPMS,'' without any 
symbol. We understand that the term ``TPMS'' is becoming commonly 
known, and, because it references the system

[[Page 18156]]

itself, it is distinct from the low tire pressure warning. We do not 
believe that VW/Audi's suggested approach of having the low pressure 
symbol inside a circle with a diagonal slash through it would provide 
sufficient clarification. In the event that the International Standards 
Organization (ISO), the Society of Automotive Engineers (SAE), or some 
other voluntary standards organization develops a symbol for TPMS 
malfunction, the agency would carefully evaluate such symbol and 
consider migration to the consensus standard as part of a subsequent 
rulemaking. We will carefully evaluate the distinctness and 
comprehensibility of any such symbol.
    We are not adopting ETV's recommendation that we require an audible 
alarm to accompany the TPMS telltale(s), because we believe that the 
requirements of the final rule provide an adequate warning to the 
driver.
    (c) Telltale Color. (i) Low Pressure Warning Telltale. The NPRM 
proposed to require a yellow telltale to indicate to the driver when a 
tire becomes significantly under-inflated (see Table 2 of FMVSS No. 
101).
    BMW commented that manufacturers should be permitted (but not 
required) to change the TPMS low pressure telltale from yellow to red 
once tire pressure becomes ``extremely low.'' BMW recommended that the 
TPMS should be allowed to change from yellow to red once the tire(s) 
drop 50 percent or more below placard pressure, a point at which the 
tire can be considered functionally flat. In its comments, BMW 
emphasized that this feature is particularly important for run-flat 
tires, because a consumer may not be able to determine by visual 
inspection or by handling feedback that the tire is flat. According to 
BMW, run-flat tires are designed to be driven with a loss of inflation 
pressure, but only at low speeds and for a limited distance; therefore, 
the consumer must be advised not to continue driving for an extended 
period of time or at highway speeds.
    VW/Audi and Emtop provided similar comments about permitting the 
low tire pressure warning to change from yellow to red at a specified 
point. VW/Audi asserted that this functionality is desirable, both as a 
matter of safety (i.e., to provide a heightened level of alert to 
indicate that the risk of tire failure is at a higher level) and as a 
matter of practicability (i.e., to permit a single location for the 
basic warning indicator and the heightened red alert).
    ETV also suggested linking a change in telltale color to a change 
in tire pressure, although at a much earlier point than other 
commenters. Specifically, ETV recommended requiring illumination of a 
yellow telltale when a tire is 20 percent below placard pressure, but 
changing the color to red (with an accompanying beep) when the pressure 
drops to 25 percent below placard pressure. ETV argued that this color 
change would not confuse drivers and that it may encourage more 
immediate action to remedy the under-inflation situation.
    For the final rule, we have decided to adopt the NPRM's proposed 
requirement for a yellow low tire pressure telltale. The issues of the 
appropriate telltale color and the possibility of changing from one 
color to another have been raised in earlier rounds of this rulemaking, 
and the commenters on the NPRM have largely reiterated arguments raised 
previously. The following summarizes our reasoning for the yellow color 
requirement.
    As we noted in the NPRM, we believe that yellow is the most 
appropriate color for the low tire pressure telltale. The use of the 
color red is usually reserved for telltales warning of an imminent 
safety hazard. An example is the brake system warning telltale, which 
is red because a failure in the vehicle's brake system results in an 
imminent safety hazard that requires immediate attention. In contrast, 
NHTSA requires a yellow telltale for driver warnings when the safety 
consequences of the malfunctioning system do not constitute an 
emergency and the vehicle does not require immediate servicing. Based 
upon the results of the agency's tire testing, we have concluded that 
yellow is the appropriate color for the low tire pressure telltale 
because it conveys the intended message that the driver may continue 
driving, but should check and adjust the tire pressure at the earliest 
opportunity.
    To respond to the commenters' requests that NHTSA permit a telltale 
that changes color from yellow to red, we are concerned that this could 
confuse consumers, particularly if it is left to the discretion of 
individual vehicle manufacturers to decide the level of under-inflation 
at which the red telltale is triggered. Conceivably, it would be 
possible for a vehicle manufacturer to program the TPMS to illuminate a 
yellow telltale for a fraction of a second, after which time, it would 
immediately turn red; such a requirement would meet the letter of the 
requirement, but foil its intent.
    As a counterpoint to ETV's argument, we believe that it is possible 
that if a driver knows that the TPMS low tire pressure warning will 
eventually shift from yellow to red, that person may elect to postpone 
taking remedial action until that time, a result quite contrary to that 
which is intended. It is conceivable that such drivers might actually 
take corrective action more quickly if they know that the illumination 
of the yellow low tire pressure telltale is the only warning that they 
will receive. However, in any case, we expect that such delayed action 
would be the anomalous response.
    Therefore, although we are retaining the yellow color requirement 
for the low tire pressure telltale, we have decided that vehicle 
manufacturers may supplement the required low pressure telltale with an 
additional warning. For example, vehicle manufacturers may choose to 
incorporate a second, red lamp to accompany the continuously-
illuminated yellow low tire pressure telltale. This red lamp could be 
illuminated when the pressure in one or more tires becomes dangerously 
under-inflated, as defined by the vehicle manufacturer. This approach 
is consistent with our traditional practice of allowing manufacturers 
to incorporate measures, consistent with Federal motor vehicle safety 
standards, which are designed to further enhance safety. If a vehicle 
manufacturer chooses to add a second, red warning lamp, its meaning and 
function would have to be discussed in the vehicle owner's manual.
    We are not adopting ETV's suggestion for requiring an audible beep 
when tire inflation pressure drops to some point lower than 25 percent 
below placard pressure, because the commenter has not provided any 
evidence to show that this redundant warning signal is necessary. 
Likewise, we are not adopting ETV's recommendation for a 20-percent 
under-inflation threshold, for the reasons discussed above.
    (ii) Malfunction Indicator Telltale. The NPRM proposed to require 
the color for the MIL to be yellow, regardless of whether it is 
incorporated in a combined telltale with the low tire pressure warning 
or is provided as a separate, dedicated telltale. For the combined 
telltale, the proposed MIL color requirement would carry through from 
the low tire pressure telltale's color requirement, and for the 
dedicated MIL, the proposed color requirement was set forth in Table 2 
of FMVSS No. 101.
    In its comments, the Alliance expressed support for requiring the 
dedicated TPMS malfunction indicator telltale to be yellow, to be 
constantly illuminated as long as the malfunction exists, and to 
perform a bulb check as required for other telltales.
    ETV stated its belief that a systemic failure of the TPMS should 
illuminate a

[[Page 18157]]

red warning telltale, because the gravity of this situation is on par 
with a tire failure.
    In the final rule, we are adopting a yellow color requirement for 
the MIL, both for the combined telltale and separate telltale options. 
As noted under the earlier discussion of the MIL, we do not believe 
that a TPMS malfunction constitutes an inherently dangerous situation 
requiring immediate corrective action, and just because the TPMS is 
malfunctioning, it does not necessarily mean that the vehicle's tires 
are under-inflated. Thus, if a yellow telltale is appropriate for the 
low tire pressure warning, we do not believe that there is 
justification for a more stringent warning for the TPMS MIL, as would 
be indicated by the color red.
    (d) Telltale Extinguishment Requirements. Under S4.2(b), the NPRM 
proposed to require that the low pressure telltale ``must extinguish 
after the inflation pressure is corrected.'' Similarly, under S4.4(a), 
the NPRM proposed to require that the TPMS malfunction telltale 
``extinguishes when the malfunction has been corrected.''
    Continental Teves commented that S4.2 is not technology-neutral 
because it does not provide for systems requiring manual reset (e.g., 
hybrid systems). It recommended that the final rule permit the telltale 
to stay illuminated until the low-pressure situation has been corrected 
and the system has been reset in accordance with any applicable 
instructions in the owner's manual.
    Schrader expressed concern that drivers will use TPMS reset buttons 
to extinguish the low pressure warning lamp without correcting the tire 
inflation problem, in order to extinguish the ``annoying'' telltale. In 
order to prevent such occurrences, Schrader stated that the final rule 
should not permit TPMSs with a manual reset feature that would allow 
consumers to recalibrate the system.
    Emtop stated that the low tire pressure warning should not be 
extinguished until the tire pressure is at least 10 percent above the 
level specified in S4.2(a) of the NPRM.
    We disagree with the comments of Continental Teves, which stated 
that S4.2 is not technology-neutral because that section does not 
specifically mention that the TPMS will be reset in accordance with any 
applicable instructions in the vehicle owner's manual. Although system 
reset was not specifically mentioned in S4.2, it is clearly addressed 
in S6(c), S6(i), S6(j), and S6(1) of the test procedures. However, in 
order to foster a better understanding of this provision, we have 
provided additional clarifying language in S4.2 of the final rule.
    We agree with Schrader that drivers should not reset the TPMS so as 
to extinguish the low tire pressure warning telltale (or the MIL) until 
the underlying problem has been corrected (e.g., restoring proper 
inflation pressure or remedying other problems). We believe that 
vehicle manufacturers will clearly address this issue when explaining 
the TPMS reset feature, if applicable. We believe that no additional 
language is necessary on this point.
    As to Emtop's recommendation that we should require the tires to be 
refilled to at least 10 percent above the level specified in S4.2(a) of 
the NPRM before permitting the telltale to extinguish, we do not 
believe that such a requirement is necessary. First, if a tire is 
inflated to a level above the TPMS low tire pressure warning threshold, 
it is presumably safe to drive. In addition, we do not believe that 
such a provision is necessary, because we would expect consumers to 
fill all four tires to the recommended inflation pressure once the low 
tire pressure telltale illuminates.
    (e) Telltale Illumination Priority. The NPRM did not provide any 
specification for telltale illumination priority for the combined TPMS 
telltale, in the event that the vehicle's TPMS encounters both a low 
tire pressure situation and a TPMS malfunction.
    Several commenters urged the agency to clarify how to prioritize 
the messages for the low tire pressure warning and the MIL in a 
combined TPMS telltale, in the event that both of the underlying 
conditions materialize simultaneously. In their comments, Fuji and 
Mitsubishi each stated that the low tire pressure warning should take 
precedence over the TPMS malfunction warning. Honda suggested that the 
flashing sequence could occur immediately before and after one minute 
of steady illumination.
    Emtop's comments suggested that, in many cases, illumination 
priority may be a non-issue, because, according to Emtop, if one of the 
telltales is operative, the other inevitably is not. Emtop stated that 
if there is a TPMS malfunction, then the low tire pressure telltale is 
unlikely to be able to provide reliable information. However, Emtop 
stated that the low tire pressure warning should take priority, if 
there is a malfunction affecting only one tire; in those cases, the 
system should continue to provide low tire pressure warnings for the 
unaffected tires, to the extent possible.
    Fuji expressed concern that if the low tire pressure warning has 
complete priority over the malfunction warning, resetting the low 
pressure telltale could clear the malfunction telltale and would 
require a complete diagnostic check cycle before illuminating the 
malfunction telltale.
    We believe that cogent arguments can be made that either the low 
tire pressure warning or the malfunction warning should be given 
priority in a combination telltale, as both messages relay important 
information to the driver. However, we would preface this discussion by 
saying that we expect that the simultaneous occurrence of a low 
pressure situation and a TPMS malfunction would be a very rare event.
    Furthermore, we believe that the ability of the TPMS to monitor 
both low tire pressure and a malfunctioning component simultaneously 
may be a derivative of system design. For example, if a vehicle were 
equipped with TPMS with a low pressure telltale that depicts a vehicle 
with a light at each wheel, the TPMS could conceivably experience a 
malfunction in the sensor for one tire (thus triggering a malfunction 
warning) but still be capable of detecting low pressure in the 
remaining three tires. In contrast, a different TPMS system might be 
equipped with a low pressure telltale that does not distinguish 
individual tires, and a malfunction in its central processing unit may 
wholly disable the system's under-inflation detection capabilities. To 
the extent that a malfunctioning system can maintain some residual 
level of under-inflation detection capability, that would be 
beneficial, but it is not a result that could be consistently expected 
across TPM systems or even from a single system at different times.
    As a result, we have decided to leave the issue of telltale 
illumination priority for the combined telltale to vehicle manufacturer 
discretion. We believe that because the manufacturers are the ones most 
familiar with the capabilities of their individual systems, they are 
the ones best equipped to handle this issue.
    (f) Supplemental Telltale. Nissan sought clarification that it 
would be permissible to install a ``continuously-flashing yellow 
light'' instead of a second, red light on vehicles equipped with run-
flat tires, in order to warn the driver when the tires have reach a 
level of under-inflation necessitating more immediate action. Nissan 
stated that the flashing light would provide a warning that the tire 
may not be appropriate for continued use, but it would not indicate the 
level of urgency associated with a red light. Nissan commented that it 
believes that its proposed continuously flashing light is sufficiently 
distinct from the TPMS combined telltale with the one-minute flashing 
sequence as to

[[Page 18158]]

permit the driver to distinguish between the two situations, and that 
the operation of the TPMS telltales would be fully explained in the 
vehicle owner's manual.
    The NPRM's discussion of how it would be permissible for a vehicle 
manufacturer to install an additional red lamp to warn when a tire is 
extremely under-inflated (as defined by the manufacturer) was intended 
to provide one example of a supplemental TPMS telltale that could be 
provided. Other supplemental telltales, such as the one suggested by 
Nissan in its comments, would also be permissible, provided that they 
do not prevent the required TPMS telltale(s) from complying with the 
standard.
    For example, for the flashing yellow lamp proposed by Nissan, we 
caution that it would not be permissible for that lamp to be 
superimposed on the required TPMS telltale(s), either the combined 
telltale or either of the separate TPMS telltales. We are concerned 
that if that were to occur, the required, continuously illuminated 
yellow low tire pressure telltale could be perceived as a flashing 
telltale. If the supplemental lamp were included in a combined TPMS 
telltale, the confusion could escalate even further. Thus, a 
supplemental telltale for TPMS must not impede or mask the 
functionality of the required TPMS telltale.
4. Tire-Related Issues
    (a) Replacement Tires and Spare Tires. As discussed above in 
further detail, the NPRM proposed to require vehicle manufacturers to 
certify that their TPMS-equipped vehicles comply with FMVSS No. 138 
with the tires installed at the time of initial vehicle sale.
    Public Citizen objected to the NPRM's approach vis-[agrave]-vis 
replacement tires, arguing that it would be feasible for vehicle 
manufacturers to recommend replacement tires that would work with the 
system and that TPMS technology should be flexible enough to 
accommodate new tires. Public Citizen argued that NHTSA should require 
vehicle manufacturers to certify that the TPMS will operate with all 
replacement tires and original equipment full-sized spare tires.
    Advocates expressed concern that if consumers install tires that 
are incompatible with the TPMS, they may elect to disable or disregard 
the TPMS MIL rather than replace the tires (presumably for reasons of 
cost). Even if tire incompatibility is a relatively uncommon event, 
Advocates argued that drivers may lose the benefits of the TPMS in 
those cases. Advocates stated that if NHTSA decides to permit 
incompatible replacement tires, the agency has an ongoing 
responsibility to determine which tires are incompatible and that this 
responsibility should not be shifted to the public. Instead, Advocates 
stated that the agency should issue frequent consumer notices regarding 
replacement tires that are incompatible with different TPMSs, perhaps 
as part of NHTSA's UTQG consumer information efforts. (A similar 
comment was provided by NADA, urging NHTSA to develop and maintain a 
comprehensive database of tire/rim combinations that would not work 
with particular TPMSs installed on certain vehicles.)
    Advocates also argued that the TPMS should be required to comply 
with the standard when a full-sized spare is mounted on the vehicle, 
and that use of a compact spare tire should trigger the TPMS MIL. 
Advocates argued that requiring that compact spares cause illumination 
of the MIL presumably would encourage the driver to replace the spare 
tire quickly with a full-sized tire.
    ETV stated that use of a spare tire should not totally disable the 
TPMS. ETV argued that although it would be preferable to have the TPMS 
monitor the spare tire as well, use of a spare tire should not mask a 
low tire pressure problem with another tire.
    The RMA commented that the number of replacement tires in use at 
any given time is very high, since tires normally will be replaced two 
or three times over the life of a vehicle. Therefore, the RMA stated 
that the TPMS should be required to function with replacement tires, 
and that permitting incompatible replacement tires is contrary to the 
purpose of the TREAD Act and could compromise consumer safety. The 
Japan Automobile Type Manufacturers Association, Inc. (JATMA) expressed 
support for the comments submitted by the RMA, including the comment on 
the need for the TPMS to continue to function properly with replacement 
tires.
    The TIA did not agree with the NPRM's approach limiting the 
standard's requirements to those tires installed on the vehicle at the 
time of initial vehicle sale. The TIA stated that in recent years, the 
number of replacement tires shipped has been about four times greater 
than the number of OE tires shipped, which supports the common 
understanding that vehicles generally outlast their OE tires. In light 
of these statistics, the TIA argued that it would be unacceptable to 
allow a TPMS to cease to function after the vehicle's tires are 
replaced, for reasons of public safety and in observance of 
congressional intent under the TREAD Act.
    The TIA reiterated its earlier comments on the TPMS rulemaking 
(submitted by the Tire Association of North America (TANA), as TIA was 
then known), in which the organization asked NHTSA to ensure that 
vehicle manufacturers provide affordable access to TPMS service 
information to all tire dealers and service providers. In its earlier 
comments, TANA stated, ``Original Equipment Manufacturers (OEMs) and 
their wholly-owned or endorsed stores should not be the only businesses 
with the ability to service or reset these systems, restricting the 
ability of consumers, tire dealers, aftermarket specialists and others 
to service these TPMSs by requiring codes, special equipment, computer 
software, or other methods of restricting automotive service.'' \33\
---------------------------------------------------------------------------

    \33\ Docket No. NHTSA-2000-8572-129.
---------------------------------------------------------------------------

    The TIA argued that without this type of information, it would be 
very difficult for an independent dealer to know how to install, 
repair, or reset each type of TPMS. It stated that tire rotation also 
could become a major problem if telltales are used that indicate each 
individual wheel, as opposed to a TPMS that simply warns of a low tire 
pressure problem generally. The TIA stated that, in order to help with 
these issues, it is in the process of developing a comprehensive TPMS 
training program for the tire industry, with the goal of bringing OE 
and aftermarket TPMS manufacturers together to compile all necessary 
information on servicing each TPMS for the benefit of any individual 
performing tire service. According to TIA, this program should be 
launched in the first quarter of 2005. Because of this program, TIA 
argued that it is appropriate for the TPMS final rule to require 
vehicle manufacturer certification that the vehicle's TPMS will 
continue to function after the OE tires are replaced.
    SEMA expressed support for NHTSA's tentative decision to apply the 
rule to only the original tires and wheels installed on the vehicle at 
the time of first sale. SEMA stated that requiring manufacturers to 
certify the vehicle under the standard with aftermarket tires and 
wheels would be unduly burdensome, although the organization urged 
NHTSA to go even further in terms of addressing burdens under the rule 
(see comments on Small Business Impacts below).
    NADA argued that no legal liability should result in cases where a 
particular tire/wheel combination cannot be

[[Page 18159]]

properly monitored by a particular TPMS. NADA stated that if tires and 
rims that meet the applicable requirements for FMVSSs directly dealing 
with such equipment are properly installed on a vehicle, the fact that 
such installation causes illumination of the TPMS MIL should not be 
considered a violation of 49 U.S.C. 30112(a), which prohibits the sale 
of noncomplying motor vehicle equipment; in such cases, the MIL would 
illuminate, but there would be no defect or noncompliance. In its 
comments, the NADA also stated that installation of incompatible 
replacement tires should not be considered a violation of 49 U.S.C. 
30122(b), because there would be no ``make inoperative'' situation 
(i.e., action to take the vehicle out of compliance with an applicable 
FMVSS) unless the repair business were to somehow override the MIL. In 
addition, NADA suggested that tire and wheel manufacturers should be 
required to certify to consumers and tire installers as to the TPMSs 
with which their tires are or are not compatible.
    Fuji requested that NHTSA adopt explicit language in the regulatory 
text of the final rule acknowledging that replacement tires and spare 
tires are not covered under the standard. Fuji recommended the 
definition of ``tire pressure monitoring system'' or paragraphs S4.2(a) 
and (b) of the NPRM as potential locations for inclusion of such a 
statement. Fuji argued that unless clarifying language is added, there 
may be confusion in the future as to which ``four tires'' must be 
monitored.
    After considering these comments related to TPMS functionality with 
replacement tires, we have decided to adopt the approach presented in 
the NPRM to require the TPMS-equipped vehicle to be certified with the 
tires originally installed on the vehicle at the time of initial 
vehicle sale. We emphasize that it would not be permissible for dealers 
to install tires on a new vehicle that would take it out of compliance 
with the TPMS standard, and to do so would violate the prohibition on 
manufacturing, selling, and importing noncomplying motor vehicles and 
equipment in 49 U.S.C. 30112. If the consumer cannot expect to acquire 
a vehicle that meets all applicable safety standards at the time of 
first purchase, the purpose of Standard No. 138, and in fact all 
Federal motor vehicle safety standards, would be severely undermined. 
Furthermore, we expect that vehicle manufacturers, in light of their 
close relationship to their dealers, would provide sufficient 
recommendations to allow dealers to install alternate tires that permit 
the TPMS to function properly.
    In order to ensure continued long-term functionality of the TPMS, 
the final rule requires a TPMS malfunction indicator capable of 
detecting when a replacement tire is installed which prevents continued 
proper functioning of the TPMS and of alerting the driver about the 
problem. (The interplay between the TPMS MIL and the activities of 
aftermarket sales and service providers related to TPMSs, including 
legal implications of those activities, are discussed below.)
    As noted in the NPRM, there are several factors that have 
contributed to our decision as to how to best ensure the long-term 
functionality of the tire pressure monitoring system. First, 
information presented to NHTSA shows that there are currently over four 
million TPMS-equipped vehicles.\34\ Neither the agency nor vehicle 
manufacturers have received reports indicating any significant 
performance problems with those TPMSs when replacement tires are 
installed on the vehicle. In addition, the agency has noted previously 
that aftermarket direct TPMSs are available and that such systems may 
be capable of functioning regardless of the construction of the 
tires.\35\ NHTSA does not have any information to suggest a significant 
problem with the operation of aftermarket TPMSs, although the 
performance capabilities of these systems are not known. This 
significant real world population of TPMSs suggests that TPMSs will 
continue to work with replacement tires in the vast majority of cases.
---------------------------------------------------------------------------

    \34\ Letter from Robert Strassburger, Vice President, Alliance 
of Automobile Manufacturers, to NHTSA (October 20, 2003) (Docket No. 
NHTSA-2000-8572-277).
    \35\ 67 FR 38704, 38731 (June 5, 2002).
---------------------------------------------------------------------------

    However, NHTSA has been presented with data demonstrating that a 
very small number of replacement tires (estimated at less than 0.5 
percent of production) may have construction characteristics and 
material content that cause the vehicle's TPMS to exhibit functional 
problems.\36\ There is no clear design solution for this problem. In 
many instances, TPMSs may function properly even when equipped with 
replacement tires with the previously discussed characteristics. 
However, to date, it has not been possible to develop an appropriate 
performance measure that would reliably identify those anomalous tires 
that would prevent proper TPMS functioning.
---------------------------------------------------------------------------

    \36\ The RMA submitted information on the prevalence of tires 
with characteristics identified as potentially being incompatible 
with proper TPMS functioning, at least in some cases. These problems 
are primarily related to the tires' construction (e.g., high carbon 
content in low aspect-ratio tires, thicker sidewall, or steel body 
ply sidewall). According to the RMA, in 2002, light vehicle tires 
having either steel body ply cords (steel casing tires) or run-flat 
capability accounted for less than 0.5 percent of tires distributed 
in the United States. (See letter from Steven Butcher, Vice 
President, Rubber Manufacturers Association, to NHTSA (October 31, 
2003) (Docket No. NHTSA-2000-8572-282)).
---------------------------------------------------------------------------

    The commenters did not provide any new information that would 
suggest that the technical problems related to TPMS functionality with 
all replacement tires have been resolved, or that it has become 
possible to identify that small subset of problematic tires that would 
prevent the TPMS from continuing to operate properly. Comments noting 
the prevalence of replacement tires in operation do nothing to resolve 
the underlying technical problems previously identified.
    Further, it is NHTSA's understanding that some of the reported 
compatibility problems between direct TPMSs and certain replacement 
tires may have been related to vehicle manufacturer use of TPMS 
transmitters and receivers produced by different suppliers.\37\ 
Incompatibility between different parts of the TPMS may have 
contributed to the overall problem in those cases. Thus, cognizance of 
this problem may limit further the number of incidents of 
incompatibility between TPMSs and replacement tires.
---------------------------------------------------------------------------

    \37\ GM submitted a letter to NHTSA on September 11, 2003, 
outlining the problems that their direct TPMS was experiencing when 
different run-flat tires were installed on the vehicle. (Docket No. 
NHTSA-2000-8572-275) Subsequent discussions revealed that TPMS 
components from different TPMS manufacturers were used and that the 
same tires permitted proper TPMS functioning when TPMS components 
from a single TPMS manufacturer were used.
---------------------------------------------------------------------------

    Based upon the above information, we now believe that there is not 
a sufficient basis to require vehicles to comply with FMVSS No. 138 
with all replacement tires. While the number of tires expected to be 
incompatible with the TPMS is small, such a requirement would 
nonetheless raise significant practicability concerns. Because no one 
is certain which tires, either produced now or in the future, will 
cause various TPMSs to malfunction, it is not practicable to require 
vehicle manufacturers to certify that the TPMS will continue to 
function properly with all replacement tires.
    We continue to believe, however, that the TPMS should continue to 
function properly beyond the point at which the vehicle's original 
tires are replaced, a clearly foreseeable event. Continued TPMS 
functionality with replacement tires is consistent with Congress' 
intention to improve tire and vehicle

[[Page 18160]]

safety, as expressed in the TREAD Act. Moreover, there are other TPMS 
failure modes (e.g., pressure sensor battery life, pressure sensor 
failure, antenna failure, TPMS power loss), and unless drivers are made 
aware of such failures, they could have a false sense of security. 
Therefore, we are adopting a requirement that the TPMS be equipped with 
a telltale indicator that would alert the driver of a TPMS malfunction, 
tire-related or otherwise. In addition, we are adopting owner's manual 
requirements to make consumers aware of this potential problem.
    In the final rule, we have decided not to require the TPMS to 
monitor the pressure in a spare tire (either compact or full-sized), 
either while stowed or when installed on the vehicle, and the agency 
will not conduct compliance testing for low tire pressure detection 
under Standard No. 138 with a spare tire installed on the vehicle. As 
we discussed in the NPRM, we have come to this decision for a number of 
reasons. First, we believe that most drivers know that temporary tires 
are not intended for extended use. Second, compact spare tires pose 
operational problems for both direct and indirect TPMSs. Such a 
requirement would be a potential disincentive for the vehicle 
manufacturer to supply a full-sized spare (or any spare tire) if TPMS 
compliance were required. In addition, it would increase the cost of 
the rule, but provide little if any safety benefit.
    However, if a spare tire is installed on the vehicle and it 
prevents the TPMS from being able to detect low tire pressure, the TPMS 
must illuminate the MIL, as it would with any other TPMS malfunction. 
We believe that such a requirement is important to remind the driver to 
replace the spare tire, either by repairing the damaged tire or 
purchasing a new replacement tire. In that way, the TPMS would 
encourage drivers not to continue driving on the spare tire for 
extended periods and to rapidly return the spare tire to its emergency 
reserve status.
    We do not agree with Fuji's comment regarding the need to include 
additional regulatory text to clarify that replacement tires are not 
covered under the standard. Unless some special provision is included, 
a FMVSS is understood to require vehicle certification with original 
equipment. However, because the vehicle may come equipped with a spare 
tire as original equipment, we have added language to the test 
conditions to clarify that the spare tire will not be installed for the 
purposes of low tire pressure testing (see S5.3.7).
    Regarding the issue of consumer awareness of replacement and 
aftermarket tires that are inconsistent with continued proper TPMS 
functionality, we believe that vehicle manufacturers and the tire 
industry will have strong incentive to make information on incompatible 
tires available to consumers and to businesses supplying automotive 
equipment and services. However, because no one is certain which tires, 
either produced now or in the future, will cause various TPMSs to 
malfunction, it is not reasonable to expect vehicle manufacturers to 
make assurances to other businesses or to consumers that the TPMS will 
continue to function properly with all replacement tires or to attempt 
to identify all incompatible tires and rims. For its part, NHTSA will 
notify vehicle manufacturers when incompatible tires are discovered 
during compliance testing, and the results of such tests are publicly 
available.
    Finally, we would address NADA's comments regarding the legal 
implications for aftermarket installers and vehicle repair businesses 
who either install aftermarket tires or rims on the vehicle or who 
service the TPMS. We would begin by noting that the TPMS standard is 
not the first to require a malfunction indicator. Malfunction 
indicators are also required under FMVSS No. 105, Hydraulic and 
Electric Brake Systems, and FMVSS No. 121, Air Brake Systems, and a 
``readiness indicator'' is required under FMVSS No. 208, Occupant Crash 
Protection. Such malfunction indicators are generally favored because 
they provide important information to consumers, as well as to 
businesses with an interest in vehicle system operations.
    Under 49 U.S.C. 30122(b), ``A manufacturer, distributor, dealer, or 
motor vehicle repair business may not knowingly make inoperative any 
part of a device or element of design installed on or in a motor 
vehicle or motor vehicle equipment in compliance with an applicable 
motor vehicle safety standard prescribed under this chapter [49 U.S.C. 
30101 et seq.] unless the manufacturer, distributor, dealer, or repair 
business reasonably believes the vehicle or equipment will not be used 
(except for testing or a similar purpose during maintenance or repair) 
when the device or element is inoperative.'' As a general matter, 
malfunction indicators can alert consumers when one of the above 
entities has made a vehicle modification that has rendered a 
functioning system inoperative. In such instances, the business 
presumably took such action inadvertently and would remedy the 
situation accordingly once the malfunction indicator is triggered.\38\ 
This principle is important, because such modifications may: (1) Make 
the monitored system itself incapable of functioning; (2) have an 
appreciable impact on vehicle safety, and (3) be relatively difficult 
for the consumer to remedy.
---------------------------------------------------------------------------

    \38\ An exception to this principle is where the monitored 
system, or a part of that system, wears out or experiences damage in 
a crash or similar event. In such cases, some intervening event 
caused the ``make inoperative'' situation, and a dealer or vehicle 
repair business is not required to bring the safety system back up 
to full compliance with an applicable FMVSS.
---------------------------------------------------------------------------

    However, the situation surrounding the TPMS malfunction indicator 
represents a special case. First, the TPMS itself is analogous to a 
malfunction indicator, because the low tire pressure telltale would 
only be expected to illuminate if the driver has failed to perform 
routine tire maintenance or if a tire has developed a leak. Therefore, 
the TPMS MIL is one step removed, essentially being a malfunction 
indicator for a malfunction indicator. In any event, even if the TPMS 
back-up system were not available, the driver could (and should) 
manually check his vehicle's tire inflation pressure on a regular 
basis.
    In situations where the TPMS MIL is detecting aftermarket or 
replacement tires or rims that prevent the continued proper functioning 
of the TPMS, such equipment arguably has not damaged the TPMS itself, 
but instead has hindered its low tire pressure detection capability. 
(Arguably, the tires themselves meet the requirements of the relevant 
FMVSSs related to tires and would be suitable for safe vehicle 
operation, absent the TPMS problem.) Once the TPMS MIL illuminates, the 
consumer would be warned that the equipment has caused a TPMS 
malfunction, and the consumer could substitute other equipment that 
would permit the TPMS to resume normal functioning.
    As noted previously, vehicle manufacturers, tire manufacturers, and 
other businesses may not know, or reasonably be able to know, exactly 
which of the many aftermarket or replacement tire and rims would 
prevent the TPMS from continuing to function properly. There are many 
tire and rim choices for a given vehicle, and a variety of businesses 
are involved in tire and rim installation and repair. In such cases, 
these businesses may only come to know of a problem once the TPMS MIL 
illuminates. Furthermore, because some TPMSs must be driven for a 
period of time in order to detect a

[[Page 18161]]

malfunction, it is quite possible that the consumer would have driven 
away from such business before the MIL illuminates.
    After the time of first sale, our primary goal for the TPMS MIL is 
to provide information and a warning to the consumer in order to ensure 
long-term operability of the TPMS. In the tire-related situations 
described above, the TPMS MIL has arguably served its purpose; the 
consumer has been warned of the compatibility problem, and the consumer 
and the installer are able to work together to resolve that problem. 
The intention is not to penalize the business for accidentally 
installing one of a very small number of incompatible replacement tires 
that are difficult to identify.
    We note that this result might be different where it can be shown 
that the installer knew of the incompatibility beforehand or took some 
other action to disable a functioning TPMS unit. In addition, we would 
point out that we believe that the TPMS MIL represents a unique case, 
and the above discussion does not alter our approach to malfunction 
indicators generally or to the other specific malfunction indicators 
referenced above.
    (b) Tire Reserve Load. Commenters representing tire manufacturers 
and sellers stated that the TPMS standard should require the low tire 
pressure telltale to illuminate before any of the vehicle's tires have 
insufficient pressure to carry the actual load on the vehicle. 
Commenters argued that because it is difficult to determine what a 
vehicle's actual load will be, the vehicle maximum load should be used 
for the relevant TPMS calculations. The RMA discussed this issue at 
length in its comments, and its arguments are summarized below. ETRTO, 
JATMA, TIA, and the Tire Rack provided similar comments that supported 
RMA's position on this issue, and AAA also supported a pressure reserve 
requirement.
    RMA argued that the NPRM was deficient and that a supplemental 
notice of proposed rulemaking (SNPRM) should be issued ``to solicit 
public comment on the need to include a requirement in the TPMS rule 
that a low tire pressure warning telltale will be activated when the 
pressure is already at a level below that required to support the 
vehicle maximum load.'' RMA said that a tire pressure reserve is 
essential, because a TPMS may instill a false sense of security in many 
consumers who may rely on the TPMS to provide an under-inflation 
warning, rather than conducting regular tire maintenance. RMA argued 
that this concern was noted by NHTSA at earlier stages of the TPMS 
rulemaking, and it cited other sources in NHTSA's TPMS docket to 
conclude that the record establishes that consumers may rely on the 
TPMS in this manner. As a result, RMA stated its belief that there is a 
high probability that tires will be operating below placard pressure, 
but above the TPMS warning threshold.
    The RMA further argued that placard pressure (upon which the low 
tire warning is based) is set by the vehicle manufacturer, and 
oftentimes for reasons such as handling and comfort, the placard 
pressure is set only slightly above the minimum pressure needed to 
carry the vehicle's maximum load. Such minimum pressures are specified 
in the load/pressure tables published by relevant tire industry 
organizations, such as those contained in the Tire & Rim Association 
Yearbook. As a result, the RMA stated that in a significant number of 
cases, by the time a vehicle's tires drop to 25 percent below placard 
pressure and the driver receives a low pressure warning from the TPMS, 
tire pressure would have dropped below the minimum pressure required to 
safely carry the vehicle's weight at maximum load. The RMA argued that 
overloaded tires in a fully-loaded condition could result in cumulative 
structural damage to the tire and an increased risk of tire failure.
    Therefore, RMA argued that in the interest of safety, NHTSA should 
adopt a tire pressure reserve requirement to ensure that the tires can 
carry the vehicle maximum load at the point at which the TPMS low tire 
pressure warning telltale illuminates. As already noted, the RMA urged 
NHTSA to issue an SNPRM to address this issue.
    In its comments, the EC stressed that the maximum load capacity and 
minimum inflation pressure compatible with the load (along with the 
speed of travel) are important factors for tire performance and safety. 
The EC stated that the pressures recommended by the tire manufacturers 
should be regarded as minima, because tires might suffer structural 
damage at pressures below those recommended pressures.
    The TRA's comments also expressed concern that the proposed rule 
would permit the vehicle to operate without a warning in situations 
where tire inflation pressure is below the minimum load/inflation 
pressure values established by the tire industry. TRA argued that the 
NPRM's approach is a deviation from other NHTSA rulemakings, which have 
incorporated language to ensure that the tire pressure is appropriate 
for the vehicle's load (e.g., requirements in FMVSS Nos. 109, New 
Pneumatic Tires, and 110, Tire Selection and Rims).
    This issue is already before the agency in a separate proceeding. 
RMA submitted a petition for rulemaking with the agency to amend FMVSS 
No. 110 to establish a tire reserve load requirement.\39\ RMA's 
comments on the NPRM reiterate the arguments raised in its petition, 
and those other commenters who addressed the tire reserve load issue 
made arguments consistent with those of RMA.
---------------------------------------------------------------------------

    \39\ Docket No. NHTSA-2002-11398-8.
---------------------------------------------------------------------------

    In response to the RMA's petition, NHTSA re-examined a 1981 NHTSA 
study of tire failure and reserve load did not demonstrate any 
correlation between failure and load,\40\ and decided to conduct a 
newer and more comprehensive study of tire failure and reserve load, 
which would reflect changes in both tires and the vehicle fleet. NHTSA 
noted in the TPMS NPRM that if new data indicate a sufficiently strong 
correlation, the agency would propose appropriate amendments to its 
standards in a separate proceeding.\41\
---------------------------------------------------------------------------

    \40\ ``The Relationship Between Tire Reserve Load Percentage and 
Tire Failure Rate,'' Crash Avoidance Division, Office of Vehicle 
Safety Standards, NHTSA (81-09-NPRM-N01-002) (1981).
    \41\ 69 FR 55896, 55914 (Sept. 16, 2004).
---------------------------------------------------------------------------

    As we noted in the NPRM, we believe that the issue of reserve load 
is a tire issue most properly considered under FMVSS No. 110, as 
amended (see 67 FR 69600 (November 18, 2002) and 68 FR 37981 (June 26, 
2003)). Instead of issuing an SNPRM, we have decided to address this 
issue in our response to the RMA's petition for rulemaking on tire 
reserve load. We are publishing a separate notice that responds to that 
petition.
    (c) Changes to Tire Publications. Because of its potential to 
impact NHTSA's TPMS and tire standards, we are taking this opportunity 
to address the comment submitted by the Tire and Rim Association \42\ 
and the related supplemental comment submitted by the Alliance \43\ 
regarding changes to the 2005 TRA Year Book. In its comment, the TRA 
expressed concern that, in its opinion, the NPRM may 
``inappropriately'' permit under-inflation of passenger car and light 
truck tires below the recommended load/inflation limits established by 
the tire industry, as reflected in the TRA Year Books. (As discussed in 
further detail below, FMVSS Nos. 109 and 110 currently reference the 
publications of a number of tire organizations, including the TRA, as 
source documents that vehicle manufacturers must consult in

[[Page 18162]]

specifying tire inflation pressure values.)
---------------------------------------------------------------------------

    \42\ Docket No. NHTSA-2004-19054-72.
    \43\ Docket No. NHTSA-2004-19054-90.
---------------------------------------------------------------------------

    The TRA stated its intention to modify its 2005 TRA Year Book by 
adding the following statement: ``If the vehicle is equipped with a 
Tire Pressure Monitoring System (TPMS), the load on the tire must not 
exceed the tire load capacity based on the inflation pressure at the 
point of illumination of the TPMS warning telltale.'' (This language 
has since been incorporated in a footnote in the 2005 TRA Year Book.)
    The Alliance's supplemental comment stated that TRA's actions 
create potential compliance problems for TPMS-equipped vehicles. The 
Alliance stated that the TRA's amendment of its Year Book in this 
fashion amounts to a unilateral attempt to modify substantive 
provisions of a vehicle safety standard. It also faulted the TRA for 
eliminating information from its Year Book about load limits at 
pressures between 20 psi and 26 psi. According to the Alliance, NHTSA 
granted a privileged status to the TRA and other tire organizations 
named in FMVSS Nos. 109 and 119, New Pneumatic Tires for Vehicles Other 
Than Passenger Cars, by authorizing those organizations' publications 
to serve as source documents for the tire load limit and other 
information required on certain vehicle labels. Other industry 
standards incorporated in FMVSSs and other NHTSA regulations refer to a 
specific version or year of issuance. According to the Alliance, the 
TRA's actions amount to an abuse of this privilege.
    The Alliance argued that the load rating information in the 
publications of the TRA and other referenced organizations have 
remained relatively stable for nearly two decades, except for 
introduction of new tire sizes, and that the information has been 
generally predictable, having been calculated on the basis of 
universally adopted formulae for tire load rating. The Alliance argued 
that the TRA's action undermines NHTSA's rulemaking authority by taking 
steps which would have the effect of modifying the threshold for 
illumination of the TPMS low tire pressure warning telltale in a manner 
consistent with the TRA's policy preference.
    In light of the above, the Alliance urged NHTSA to clarify in the 
final rule for TPMS that the footnote in the 2005 TRA Year Book related 
to TPMS-equipped vehicles has no regulatory significance and does not 
affect the tire load rating for purposes of S4.3.1(c) of FMVSS No. 110 
and the related provision in FMVSS No. 120, Tire Selection and Rims for 
Motor Vehicles Other Than Passenger Cars. In addition, the Alliance 
requested that NHTSA amend FMVSS Nos. 109, 119, and 139, New Pneumatic 
Tires for Light Vehicles, to specify use of the 2004 publications of 
the listed tire organization in those tire standards as the appropriate 
sources for determining permissible tire load ratings. The Alliance 
argued that good cause exists for so amending FMVSS Nos. 109, 119, and 
139 without notice and comment, because of the potential compliance 
problems that could arise upon publication of the 2005 TRA Year Book. 
In the alternative, the Alliance asked that its supplemental comment be 
treated as a petition for rulemaking to amend FMVSS Nos. 109, 119, and 
139.
    We would begin by briefly explaining the relevant requirements 
currently contained in our safety standards for tires and our reasoning 
for referencing certain tire industry publication without a specific 
year or volume designation. Paragraph S4.4.1 of FMVSS No. 109 requires 
that each tire manufacturer make available to the public information on 
the rims that may be used with each tire that it produces.\44\ Such 
information may: (1) Take the form of a list that must be furnished to 
dealers of the manufacturer's tires, NHTSA, and any person upon 
request; or (2) be contained in a publication by one of the following 
organization: (a) The Tire and Rim Association; (b) the European Tyre 
and Rim Technical Organization; (c) the Japanese Automobile Tyre 
Manufacturers Association; (d) Deutsche Industrie Norm; (e) the British 
Standards Institution; (f) the Scandinavian Tire and Rim Organization; 
and (g) the Tyre and Rim Association of Australia. In most instances, 
the relevant information is listed in one of these industry 
publications.
---------------------------------------------------------------------------

    \44\ Similar requirements are contained in S5.1 of FMVSS No. 119 
and S4.1.1 of FMVSS No. 139.
---------------------------------------------------------------------------

    The current requirements, discussed above, were adopted in 1981, 
when NHTSA amended its tire standards to authorize the publications of 
the organizations listed above to serve as the source documents for 
tire load limits and other tire safety information.\45\ The purpose of 
this rulemaking action was to expedite the introduction of new tires to 
the market. (Before the 1981 amendment to the tire standards, tire 
manufacturers were required to petition NHTSA each time they intended 
to introduce new tires. NHTSA maintained a listing of all registered 
tires in Table 1, Appendix A of FMVSS No 109.) The current system 
worked predictably and generated little controversy until now.
---------------------------------------------------------------------------

    \45\ See 46 FR 61473 (Dec. 17, 1981).
---------------------------------------------------------------------------

    However, the TRA's recent action (i.e., amending its 2005 Year Book 
by incorporating additional text in a footnote to its tire selection 
procedure) represents a de facto substantive change to our tire placard 
requirements. This change could have an impact on vehicle 
manufacturers' tire and rim selections, because FMVSS Nos. 110 and 120 
require vehicle manufacturers to rely on information provided by the 
tire industry. Specifically, S4.3.1(c) of FMVSS No. 110 allows vehicle 
manufacturers to recommend a lower-than-maximum tire inflation pressure 
so long as the tire load does not exceed the tire load rating appearing 
in one of the publications described in S4.4.1(b) of FMVSS No. 109.\46\ 
Because the new TRA language may change how the tire load information 
is calculated, this represents a substantive change to our tire safety 
information regulations.
---------------------------------------------------------------------------

    \46\ Similar requirements are contained in S5.1 of FMVSS No. 
120.
---------------------------------------------------------------------------

    Only NHTSA has the authority to amend the FMVSSs pertaining to 
tires. Any substantive changes to our regulations, including ones 
involving maximum tire load formulae, require agency action, as well as 
notice and comment. Because no such action has taken place and because 
TRA's above-discussed amendment to its 2005 Year Book may affect our 
regulations, we believe that it is necessary to clarify the regulatory 
effect of the TRA's footnote.
    In order to avoid the impermissible regulatory effect of the TRA's 
footnote, we are clarifying that the provisions of FMVSS Nos. 110 and 
120 pertaining to tire selection only require vehicle manufacturers to 
consult the numerical values contained in the load/pressure tables 
provided in the publications of the enumerated tire industry 
organizations. Thus, the footnote related to TPMSs in the 2005 TRA Year 
Book has no legal or regulatory effect.
    We caution the tire organizations referenced in our tire standards 
that action to achieve the footnote's results through direct 
manipulation of the values in the load/pressure tables would have the 
equally impermissible effect of amending our tire standards. If that 
were to occur, the agency would be forced to consider other options, 
such as specifying a specific year(s) for these tire industry 
publications (e.g., 2000 or later), reverting to the prior system under 
which tire manufacturers would be required to petition the agency 
before introducing new tires, or publishing the equations for 
calculation of recommended tire pressures (thereby

[[Page 18163]]

allowing vehicle manufacturers to directly recommend pressures).
    (d) Minimum Activation Pressure. Paragraph S4.2 of the NPRM 
proposed to require that the TPMS must illuminate a low tire pressure 
warning telltale not more than 10 minutes after the inflation pressure 
in one or more of the vehicle's tires, up to a total of four tires, is 
equal to or less than either the pressure 25 percent below the vehicle 
manufacturer's recommended cold inflation pressure, or the pressure 
specified in the third column of Table 1, Low Tire Pressure Warning 
Telltale--Minimum Activation Pressure, whichever is higher. Table 1 
proposed minimum activation pressures (MAPs) for different tires, based 
upon: (1) Tire type, and (2) maximum or rated inflation pressure. The 
specified tire types included P-metric (Standard Load), P-metric (Extra 
Load), Load Range ``C,'' Load Range ``D,'' and Load Range ``E.''
    In general, the proposed MAPs in Table 1 were based on the lowest 
inflation pressure values provided in the TRA, JATMA, and ETRTO Year 
Books for loads specified, as well as available information on minimum 
activation pressures for TPMSs. The relevant tire industry Year Books 
in 2000 consistently reported low pressure values down to 140 kPa (20 
psi) for standard P-metric tires.
    However, the agency found that for light truck tires, the low 
values reported in the tire industry Year Books were not consistent, 
although further analysis demonstrated that minimum pressure values 
were approximately 58 percent of the maximum inflation pressure for the 
tires. Therefore, the agency utilized this formula in proposing values 
for LT tires in Load Ranges ``C,'' ``D,'' and ``E.'' \47\
---------------------------------------------------------------------------

    \47\ We note that the TRA 2000 Year Book did report values lower 
than 58 percent for some LT tires. However, the agency believes that 
at 58 percent below the maximum pressure, most tires would be 
significantly under-inflated for most vehicle applications. 
Consequently, we did not propose MAPs for LT tires below this level.
---------------------------------------------------------------------------

    In its comments, the Alliance requested that, as part of the final 
rule, the agency respond to the Alliance's earlier petition for 
rulemaking \48\ seeking revision of Table 1 for minimum activation 
pressures for vehicles with Load Range ``C,'' ``D,'' and ``E'' light 
truck tires. The Alliance's petition stated that the MAPs currently 
contained in Table 1 do not allow tires (particularly Load Range ``D'' 
and ``E'' tires) to be used across the safe operating ranges of 
inflation pressures for which loads are specified in the Tire and Rim 
Association Yearbooks. According to the Alliance, on some vehicles such 
as 15-passenger vans and large pick-up trucks with a large differential 
between front and rear GAWRs, the front tires may be over-specified for 
the load they carry. In such cases, vehicle manufacturers may specify 
tires that are appropriate for the heaviest axle (i.e., the rear axle), 
thereby minimizing potential consumer confusion related to different 
front and rear placard pressures and different front and rear 
replacement tires. The Alliance argued that the MAPs proposed in Table 
1 for LT Load Range ``C,'' ``D,'' and ``E'' tires are set too close to 
the placard pressure for these vehicle applications and, accordingly, 
should be set at lower values.
---------------------------------------------------------------------------

    \48\ Docket No. NHTSA-2000-8572-265.
---------------------------------------------------------------------------

    The Alliance argued that for Load Range ``D'' and ``E'' tires, 
field performance data and other test data show that there is no safety 
need for the MAPs for these tires currently contained in Table 1, and 
in fact, the Alliance stated that the currently listed MAPs for those 
tires could actually have adverse safety implications. According to the 
Alliance, the MAPs recommended in its petition as revisions to Table 1 
would allow LT tires to be used safely in different load applications 
in a manner consistent with the TRA Yearbook. The Alliance's petition 
asserted that if the agency retains Table 1 as proposed, it ``would 
necessitate significant vehicle redesigns, cost penalties, and adverse 
safety and non-safety effects that are not justified by any safety 
need.''
    Based upon the above, the Alliance's petition requested 
modification of Table 1 to set minimum activation pressure for LT tires 
based upon the vehicle's load range. For example, if a Load Range ``E'' 
tire were used in a Load Range ``D'' application, the Load Range ``D'' 
minimum activation pressure could be used for TPMS activation purposes. 
For a more complete explanation, readers should consult the Alliance's 
petition.
    Alternatively, the Alliance stated that if the petition for 
rulemaking related to MAPs could not be resolved in time for issuance 
as part of the final rule, NHTSA should not specify MAPs for the 
affected vehicles and instead defer implementation of the MAP 
requirements for those vehicles until rulemaking can be conducted at a 
later date.
    The major vehicle manufacturers that commented on the MAP issue 
supported the Alliance petition and the arguments raised therein. 
DaimlerChrysler stated that the NPRM does not accommodate vehicles that 
require multiple tire pressures for different driving conditions (i.e., 
Load Range ``C,'' ``D,'' and ``E'' tires). DaimlerChrysler commented 
that the MAPs for LT tires in Load Ranges ``D'' and ``E'' in Table 1 
are 38 psi and 46 psi, respectively, but that it uses these tires in 
applications with a placard pressure of 40 psi. Thus, DaimlerChrysler 
requested that the MAP for these tires be set at 35 psi, a value 
consistent with the TRA minimum recommended pressure for those tires. 
(However, in a supplementary comment dated February 8, 2005, 
DaimlerChrysler subsequently retracted its support for a MAP set at 35 
psi for Load Range ``D'' and ``E'' tires.\49\ In that letter, 
DaimlerChrysler stated that it supports a solution consistent with the 
recommendation in the Alliance's petition for rulemaking on the MAP 
issue.)
---------------------------------------------------------------------------

    \49\ Docket No. NHTSA-2004-19054-89.
---------------------------------------------------------------------------

    In its comments, DaimlerChrysler also provided its view of the 
practical implications of the MAP issue. It stated that if proposed 
Table 1 were adopted without change, vehicle manufacturers' current 
practices for use of Load Range ``C,'' ``D,'' and ``E'' tires would 
result in the low tire pressure telltale being illuminated much of the 
time when the vehicle is lightly loaded. DaimlerChrysler argued that 
this situation could result in desensitization of the driver and that 
such drivers may lose the benefits of the TPMS. DaimlerChrysler further 
argued that this situation would leave vehicle operators with the 
choice of ignoring the safety warning, permanently disabling the 
warning, or over-inflating their tires.
    DaimlerChrysler suggested that the vehicles in question could be 
equipped with a driver-selectable TPMS. DaimlerChrysler stated that 
this mechanism would make TPMSs technology-neutral and tire type-
neutral, because the driver (or the service shop) could set the 
reference pressure based on the load, driving conditions, or 
recommended replacement tire pressure. According to DaimlerChrysler, 
such a system would provide a reliable warning when there is a pressure 
loss of 25 percent under this reference level.
    DaimlerChrysler suggested that if NHTSA is not prepared to address 
this MAP issue quickly, the final rule could defer the rulemaking's 
requirements for trucks greater than 8,500 pounds (3,856 kg) (not 
passenger cars or MPVs) to allow more time to respond to the issue.
    General Motors stated that it conducted tests of four vehicles 
using lightly-loaded and GVWR loading conditions. GM stated that the 
vehicles were tested both at the recommended pressures and at the 
increased pressures that would be required by the proposed MAPs in 
Table 1. According to GM, the

[[Page 18164]]

higher pressures resulted in adverse effects, including decreased 
rollover resistance, reduced understeer (2 vehicles), increased 
response time (2 vehicles), and degraded on-center handling (3 
vehicles). GM commented that the MAPs currently proposed could provide 
a disincentive for vehicle manufacturers to select tire types that 
exceed load-carrying requirements for particular vehicle applications, 
resulting in lower load range tire types for some vehicle models than 
would otherwise have been chosen.
    The issues raised by the Alliance's petition related to MAPs 
involve a key aspect of the low tire pressure warning provided by the 
TPMS, in that the MAP represents a threshold value for maintaining safe 
tire operation, because a higher MAP could provide an earlier warning 
to the driver. Although the MAP issue raised by the Alliance is only 
expected to impact a small percentage of vehicles using LT tires (i.e., 
typically vehicles with a GVWR of over 8,500 pounds), the agency must 
fully understand the potential rollover and handling implications of 
the final values it selects for the MAPs. This is particularly true for 
vehicle applications where the recommended inflation pressure is close 
to the MAP or where it is much lower than the maximum inflation 
pressure. For example, 15-passenger vans and some pickup trucks may 
have a greater propensity for rollover when their tires are 
significantly under-inflated, so prompt application of FMVSS No. 138 
(with appropriate MAPs) to such vehicles is important for achieving the 
safety benefits of the TPMS standard. The agency is currently analyzing 
the issue of minimum activation pressures for LT tires, and it is our 
intention to respond to the Alliance's petition on MAPs as part of a 
separate rulemaking.
    We would emphasize that vehicles equipped with LT tires load range 
``D'' and ``E'' must be equipped with a TPMS that conforms to the 
requirements of FMVSS No. 138. However, in the interim period, we have 
decided to alter the MAPs listed in Table 1 for load range ``D'' and 
``E'' tires from the values proposed in the NPRM. As the commenters 
pointed out, the TRA Yearbooks report load rating values for LT load 
range ``D'' and ``E'' tires as low as 35 psi. Hence, according to the 
TRA, these tires can be used at that inflation pressure at the 
specified load rating. Therefore, we are adopting a MAP of 35 psi for 
LT Load Range ``D'' and ``E'' tires as part of this final rule. (The 
values for P-metric and LT Load Range ``C'' tires are unchanged from 
the NPRM.)
    Once the agency completes its analysis of the relevant data, the 
MAP values set forth in this final rule will be either confirmed or we 
will propose to modify them as part of our rulemaking response to the 
Alliance's petition.
5. Owner's Manual Requirements
    Paragraph S4.5 of the NPRM proposed to require each certified 
vehicle to provide an image of the low tire pressure telltale symbol 
(and an image of the TPMS malfunction telltale symbol, if a dedicated 
telltale is utilized for this function) and the following specific, 
standardized statement in English regarding the presence of a TPMS in 
the vehicle and its function:

    Each tire, including the spare (if provided), should be checked 
monthly when cold and inflated to the inflation pressure recommended 
by the vehicle manufacturer on the vehicle placard or tire inflation 
pressure label. (If your vehicle has tires of a different size than 
the size indicated on the vehicle placard or tire inflation pressure 
label, you should consult the appropriate section of this owner's 
manual to determine the proper tire inflation pressure.) When the 
low tire pressure telltale is illuminated, one or more of your tires 
is significantly under-inflated. You should stop and check your 
tires as soon as possible, and inflate them to the proper pressure. 
Driving on a significantly under-inflated tire causes the tire to 
overheat and can lead to tire failure. Under-inflation also reduces 
fuel efficiency and tire tread life, and may affect the vehicle's 
handling and stopping ability.
    Your vehicle has also been equipped with a TPMS malfunction 
telltale to indicate when the system is not operating properly. When 
the malfunction telltale is illuminated, the system may not be able 
to detect or signal low tire pressure as intended. TPMS malfunctions 
may occur for a variety of reasons, including the installation of 
incompatible replacement tires on the vehicle. Always check the TPMS 
malfunction telltale after replacing one or more tires on your 
vehicle to ensure that the replacement tires are compatible with the 
TPMS.

    That paragraph of the NPRM also proposed to permit the owner's 
manual to include additional information about the significance of the 
low tire pressure warning telltale illuminating, a description of 
corrective action to be undertaken, whether the tire pressure 
monitoring system functions with the vehicle's spare tire (if 
provided), and how to use a reset button, if one is provided (S4.5(b)). 
For vehicles that do not come with an owner's manual, the NPRM proposed 
to require the mandatory information to be provided in writing to the 
first purchaser (S4.5(c)).
    In its comments, Nissan argued that the NRPM's proposed owner's 
manual statement is restrictive and would prevent manufacturers from 
tailoring the TPMS discussion in the owner's manual to the specific 
system installed on the vehicle. Nissan stated that NHTSA should 
refrain from adopting specific owner's manual language for TPMS, but 
instead provide requirements for its general content (i.e., alerting 
consumers regarding: (1) Potential problems related to compatibility 
between the vehicle's TPMS and various types of replacement tires, and 
(2) the presence and operation of the TPMS malfunction indicator).
    Nissan stated that if the agency nevertheless decides to adopt 
specific owner's manual language similar to that proposed in the NPRM, 
the following points should be considered. First, Nissan expressed 
concern about the use of the terms ``compatible'' and ``incompatible 
replacement tires'' without defining those terms. Nissan stated that 
consumers could be misled unless they are made aware that the purpose 
of this warning is to inform the consumer that the construction or 
other design characteristics of some replacement tires may cause the 
TPMS to experience inadequate signal reception. Accordingly, Nissan 
recommended that additional language be added to clarify the terms 
compatible/incompatible in the owner's manual language.
    Nissan commented that the proposed owner's manual language seemed 
to focus on systems with a separate TPMS MIL telltale, without 
discussion of TPMSs providing a combination low pressure/malfunction 
telltale. Nissan argued that as proposed, the owner's manual language 
could confuse consumers whose vehicles are equipped with a combination 
telltale, so its comments stated that the owner's manual language 
should be revised to also include a discussion of the combination 
telltale. The comments of AIAM, Fuji, and Suzuki raised similar 
arguments.
    In its comments, Nissan also recommended that the following 
sentence from the proposed owner's manual language not be included in 
the final rule: ``If your vehicle has tires of a different size than 
the size indicated on the vehicle placard or tire inflation pressure 
label, you should consult the appropriate section of this owner's 
manual to determine the proper tire inflation pressure.'' Nissan stated 
that there is not currently any requirement to include in the owner's 
manual information regarding tire sizes other than those included as 
original equipment on the vehicle. According to Nissan, vehicle 
manufacturers do not and cannot provide such information for

[[Page 18165]]

all tires that might conceivably be used in wheel/tire/inflation 
pressure combinations not designed by the vehicle manufacturer, but 
which the consumer may nonetheless choose to install. Nissan expressed 
concern that such a statement could confuse consumers whose owner's 
manual does not include supplemental tire information.
    SEMA recommended four modifications to the proposed owner's manual 
language. First, it stated that the owner's manual language should 
reflect the fact that the recommended tire pressure for the originally-
installed tires may not be applicable to certain replacement tire/wheel 
combinations. Therefore, SEMA recommended adding a statement to 
``select a tire pressure that considers the vehicle's loading 
characteristics and is appropriate for the wheel and tire combination 
installed on the vehicle.''
    Second, SEMA stated that the proposed owner's manual language 
alerts the consumer that replacement tires may trigger the TPMS 
malfunction telltale, but that it does not specifically address 
combined wheel/tire packages. SEMA argued that because consumers 
frequently replace both the vehicle's tires and wheels and also can 
replace the wheels while maintaining the original tires, the owner's 
manual language should add the term ``wheels'' (to read ``tires or 
wheels'') in order to avoid any consumer confusion.
    Third, SEMA objected to the term ``incompatible'' to describe 
replacement tires whose installation causes the TPMS malfunction 
indicator to activate. SEMA seems to be arguing that the replacement 
tires (and/or wheels) may be an appropriate match in terms of 
supporting the vehicle, but the construction nevertheless may prevent 
the TPMS from functioning properly. Accordingly, SEMA recommended 
substituting the word ``alternate'' for ``incompatible.''
    Fourth, SEMA recommended that the owner's manual should note that 
dealers, retailers, and installers should have access to all service 
information necessary to make the alternate tires and wheels operate 
correctly in conjunction with the TPMS malfunction indicator lamp. 
However, SEMA stated that this recommendation would apply only if NHTSA 
mandates that vehicle manufacturers share such service information with 
other relevant parts and service suppliers.
    Sumitomo urged NHTSA to modify the proposed owner's manual language 
to reflect the responsibility of the vehicle operator to maintain the 
correct tire pressure. Sumitomo argued that the NPRM could be 
interpreted as shifting this responsibility to the vehicle 
manufacturer. Therefore, Sumitomo proposed that the following 
additional statement be required in the owner's manual: ``The vehicle 
operator has the responsibility to maintain the correct tire pressure 
even though the tire pressure indicator warning may not be illuminated 
due to the lower than specified tire pressure.'' Sumitomo also 
recommended adding a statement to reflect the fact that the TPMS itself 
will not maintain correct tire pressure.
    Consistent with Sumitomo's comments immediately above, the RMA 
stated that the owner's manual should include language explicitly 
stating that the TPMS does not verify that proper tire pressure is 
maintained (i.e., even when the TPMS telltale is not illuminated, the 
tires may not be at optimum pressure). The RMA expressed concern that 
the NPRM's proposed owner's manual language could induce consumers to 
substitute reliance on the TPMS for routine tire maintenance.
    The TIA stated the owner's manual should require a statement that 
even for a TPMS-equipped vehicle, the vehicle operator should check the 
tires regularly for proper inflation pressure and tread depth and 
should rotate the tires every 6,000 miles for optimum performance and 
fuel economy.
    NADA questioned the NPRM's discussion of vehicles without an 
owner's manual, which NADA thought might refer to used vehicles (see 69 
FR 55896, 55906 (Sept. 16, 2004)). NADA commented that NHTSA does not 
have authority to require point-of-sale dissemination of TPMS 
information other than through the vehicle owner's manual.
    Particularly for a new safety standard for a device whose function 
might not be apparent to the average driver, we believe that a clear 
and consistent written statement in the vehicle's owners manual is 
necessary to explain the benefits and limitations of the TPMS and the 
driver's responsibility to maintain proper tire pressure. Consequently, 
as part of this final rule, we are including a required statement in 
the owner's manual (or in writing to the first purchaser for vehicles 
without an owner's manual).
    In response to NADA's comments, we would clarify that this 
requirement only applies to new vehicles. Regarding NADA's comment 
about the requirement for a statement in writing outside the owner's 
manual (in cases where there is no owner's manual), we believe that 
this TPMS-related information is important and must be provided to the 
first purchaser. However, rather than requiring that vehicle 
manufacturers provide an owner's manual, we believe that it is 
preferable to allow vehicle manufacturers the flexibility to instead 
provide this information through a written statement.
    We disagree with the comment of Nissan that the proposed owner's 
manual language is overly restrictive and would prevent vehicle 
manufacturers from tailoring the owner's manual discussion of the TPMS 
to the specific system installed on the vehicle. Paragraph S4.5(b) of 
the NPRM proposed to permit manufacturers to discuss a variety of 
issues related to the operation of their particular system. We believe 
that requiring a specified statement in the owner's manual in the final 
rule does not diminish the ability of vehicle manufacturers to provide 
explanation of the TPMS and its operation.
    In response to public comments, we have made some modifications to 
the NPRM's proposed owner's manual statement. We have modified our 
discussion of ``incompatible'' replacement tires. We recognize that 
replacement tires may be compatible with the vehicle in terms of 
carrying the maximum vehicle load, but may nevertheless be incompatible 
with continued proper TPMS functioning. However, replacement tires that 
prevent proper TPMS functioning are indeed incompatible with the TPMS. 
With that said, we have revised the owner's manual statement to provide 
further clarity. We have also modified the owner's manual statement to 
reflect the fact that drivers frequently replace both the vehicle's 
tires and wheels (rims).
    We have decided to include tailored language reflecting the fact 
that there are two options for the MIL, a dedicated TPMS malfunction 
telltale or inclusion as part of a combined low tire pressure/TPMS 
malfunction telltale.
    We agree with Nissan that vehicle manufacturers are unlikely to 
provide recommended inflation pressures for every possible replacement 
tire in the vehicle owner's manual. However, it remains important for 
consumers to inflate their tires to a pressure level appropriate for 
those tires. Accordingly, we have modified the relevant statement in 
the owner's manual to delete the statement regarding consultation with 
the owner's manual to find such alternate tire pressures. We expect 
that consumers will be able to easily obtain the relevant pressure 
information from tire industry sources.
    We agree with Sumitomo that it remains the driver's responsibility 
to maintain proper tire inflation pressure

[[Page 18166]]

and that the TPMS is not designed to signal as soon as the tires have 
deviated from the optimal inflation level, and we have added language 
to stress the importance of proper tire maintenance. Regarding 
Sumitomo's other comments that the TPMS is a detection device that does 
not act to add air itself to maintain inflation pressure, we believe 
that in the future, TPMSs may become available that combine under-
inflation detection and re-inflation features; accordingly, we have 
decided not to opine as to future TPMS capabilities in this regard. We 
also agree with SEMA that some replacement tires may call for an 
inflation pressure different than that of the OE tires that is 
reflected on vehicle placard. The owner's manual statement has been 
revised to include language related to these points.
    We have decided not to adopt TIA's recommended language concerning 
tire maintenance advice related to checking tread depth and rotating 
the tires every 6,000 miles. Although this information may be useful 
for voluntary inclusion in the owner's manual, we do not believe that 
it is necessary to require such language for the following reasons. 
First, we believe that discussion of other aspects of tire maintenance 
is outside the scope of the TPMS rulemaking. In addition, we believe 
that there may be reasonable differences of opinion regarding proper 
tread depth or frequency of tire rotation. We do not agree with the 
TIA's conclusion that consumers cannot be trusted to consult their 
vehicle's owner's manual in appropriate situations.
    Regarding SEMA's recommendation to require vehicle manufacturers to 
make TPMS information available to tire retailers and dealers and to 
provide related language in the owner's manual, we are addressing that 
issue in this notice under section IV.C.8. Please consult that section 
for further details.
    Accordingly, we have decided to require the following statement, in 
English, in the vehicle's owner's manual (or in writing for the first 
purchasers of vehicles without an owner's manual):

    Each tire, including the spare (if provided), should be checked 
monthly when cold and inflated to the inflation pressure recommended 
by the vehicle manufacturer on the vehicle placard or tire inflation 
pressure label. (If your vehicle has tires of a different size than 
the size indicated on the vehicle placard or tire inflation pressure 
label, you should determine the proper inflation pressure for those 
tires.)
    As an added safety feature, your vehicle has been equipped with 
a tire pressure monitoring system (TPMS) that illuminates a low tire 
pressure telltale when one or more of your tires is significantly 
under-inflated. Accordingly, when the low tire pressure telltale 
illuminates, you should stop and check your tires as soon as 
possible, and inflate them to the proper pressure. Driving on a 
significantly under-inflated tire causes the tire to overheat and 
can lead to tire failure. Under-inflation also reduces fuel 
efficiency and tire tread life, and may affect the vehicle's 
handling and stopping ability.
    Please note that the TPMS is not a substitute for proper tire 
maintenance, and it is the driver's responsibility to maintain 
correct tire pressure, even if under-inflation has not reached the 
level to trigger illumination of the TPMS low tire pressure 
telltale.
    [The following paragraph is required for all vehicles certified 
to the standard starting on September 1, 2007 and for vehicles 
voluntarily equipped with a compliant TPMS MIL before that time.] 
Your vehicle has also been equipped with a TPMS malfunction 
indicator to indicate when the system is not operating properly. 
[For vehicles with a dedicated MIL telltale, add the following 
statement: The TPMS malfunction indicator is provided by a separate 
telltale, which displays the symbol ``TPMS'' when illuminated.] [For 
vehicles with a combined low tire pressure/MIL telltale, add the 
following statement: The TPMS malfunction indicator is combined with 
the low tire pressure telltale. When the system detects a 
malfunction, the telltale will flash for approximately one minute 
and then remain continuously illuminated. This sequence will 
continue upon subsequent vehicle start-ups as long as the 
malfunction exists.] When the malfunction indicator is illuminated, 
the system may not be able to detect or signal low tire pressure as 
intended. TPMS malfunctions may occur for a variety of reasons, 
including the installation of replacement or alternate tires or 
wheels on the vehicle that prevent the TPMS from functioning 
properly. Always check the TPMS malfunction indicator after 
replacing one or more tires or wheels on your vehicle to ensure that 
the replacement or alternate tires and wheels allow the TPMS to 
continue to function properly.

    Vehicle manufacturers may include information in the owner's manual 
about the time for the TPMS telltale(s) to extinguish once the low tire 
pressure condition or the malfunction is corrected. They may also 
include information in the owner's manual about the significance of the 
low tire pressure warning telltale illuminating, a description of 
corrective action to be undertaken, whether the TPMS functions with the 
vehicle's spare tire (if provided), and how to use a reset button (if 
one is provided).
6. Test Procedures
    As a general comment, the Alliance argued that the NPRM's test 
procedures may not be sufficiently technology-neutral so as to 
accommodate developing and advanced TPMS technologies. In response, we 
note that it is NHTSA's practice to issue performance standards that 
meet the need for motor vehicle safety, are practicable, and are stated 
in objective terms. Although NHTSA tries to develop standards that are 
technology-neutral, that does not mean that we will sacrifice safety in 
order to accommodate every available technology. However, when public 
comments identify areas where an NPRM, such as the one for FMVSS No. 
138, could be refined to promote advanced technologies without 
sacrificing safety, we will consider those comments carefully. Other 
specific comments related to the NPRM's test procedures are addressed 
below.
    (a) Calibration Time. Under paragraph S6(d), the NPRM proposed a 
cumulative driving time of not less than 20 minutes for the ``system 
calibration/learning phase,'' which would include driving the vehicle 
in two directions on the test course. The NPRM proposed that time would 
not be accumulated while the vehicle's brakes are being applied.
    Schrader commented that a calibration/learning phase should not be 
necessary, regardless of the technology used. According to Schrader, 
because calibration requires a significant amount of user knowledge and 
interaction to ensure proper performance, the TPMS should be ready to 
use and fulfill its intended purpose without user interaction. Schrader 
argued that the only time a calibration phase should be necessary is 
when a malfunctioning system has been repaired by a qualified 
technician and needs to be recalibrated in order to restore proper 
performance.
    Sumitomo recommended that the time period for specified calibration 
in the test procedures should be increased to one hour, in order to 
reasonably accommodate indirect TPMSs and thereby keep the standard 
technology-neutral. Sumitomo stated that indirect TPMSs require a 
calibration time of at least 30 minutes under good conditions to detect 
25-percent under-inflation in multiple tires, but that one hour is 
preferable in order to account for the variety of circumstances the 
system may encounter.
    NIRA also recommended increasing the calibration time to one hour, 
in order to be comparable with NIRA's recommended detection time for 
low tire pressure. NIRA argued that the additional calibration time 
would not affect the life-saving potential of TPMSs. It also 
recommended that the final rule explicitly state that the calibration 
procedure will be conducted at normal driving speeds, at a varied speed 
profile, and without engagement of cruise control (if equipped).
    For the final rule, NHTSA has decided to retain a 20-minute time

[[Page 18167]]

period for TPMS calibration as part of the standard's test procedures. 
We believe that a 20-minute time period is appropriate in order to 
provide a technology-neutral standard that accounts for the need of 
some TPMSs to have time to calibrate the system when the vehicle is 
new, when new tires are installed, and when a tire is replaced or 
rotated. We do not agree with Schrader's comment that calibration would 
require a significant amount of user knowledge and interaction to 
ensure proper performance. Not all TPMSs require calibration, and for 
those that do, a driver would most likely need to press a reset button 
at an appropriate point, as described in the owner's manual. We do not 
believe that this process would be difficult or require any specialized 
knowledge.
    However, we are not adopting commenters' suggestions to increase 
the calibration time in the test procedures. We believe that an 
excessively long calibration period would increase the likelihood that 
a tire could develop a leak during calibration that would go 
undetected. Available information suggests that most TPMSs requiring 
calibration could do so within this 20-minute time period, so we do not 
see any reason to delay the timing for the TPMS to begin providing low 
tire pressure warnings to the driver.
    In response to NIRA's comment that the calibration procedure should 
be conducted at normal driving speeds, at a varied speed profile, and 
without engagement of cruise control (if equipped), we note that the 
final rule's test procedures provide for a cumulative driving time of 
20 minutes within a speed range of 50-100 km/hr. We believe that this 
speed range is adequate for proper TPMS calibration. However, we agree 
with the commenter that use of cruise control during calibration could 
provide the TPMS with a large amount of redundant information, as 
compared to information obtained while driving at different speeds, and 
we also believe that it is important to ensure that the system performs 
properly over a range of speeds, an objective that could be foiled by 
the use of cruise control in this context. Accordingly, we have 
included a statement in S5.3.2 that for vehicles equipped with cruise 
control, cruise control will not be engaged during testing.
    (b) Driving Conditions. Under the test procedures section, the NPRM 
proposed that the ambient temperature for testing would be between 
0[deg] C (32[deg] F) and 40[deg] C (104[deg] F) (see S5.1) and that the 
road surface would be dry during testing (see S5.2). It also proposed 
that the vehicle's TPMS would be calibrated and tested at speeds 
between 50 km/h (31.1 mph) and 100 km/h (62.2 mph) (see S5.3.2). The 
NPRM proposed that testing would be conducted on any portion of the 
Southern Loop of the Treadwear Test Course defined in Appendix A and 
Figure 2 of 49 CFR 575.104. The RMA commented that the TPMS test 
conditions and performance parameters should be expanded to capture a 
fuller range of real world driving conditions. (AAA and ETRTO provided 
similar comments.) Accordingly, the RMA argued that the temperature 
range for testing should be expanded to include ambient temperatures 
below freezing (32[deg] F) and above 104[deg] F. The RMA also advocated 
testing under slippery road conditions and increasing the range for the 
driving speed to include speeds over 100 km/hr for low tire pressure 
detection. The RMA argued that as currently proposed, the TPMS test 
procedures would not test at higher speeds (arguably when the TPMS is 
most important), on wet/snowy/icy roadways, under extreme temperatures, 
on secondary roads, or during turning or braking maneuvers. RMA stated 
that these conditions do not occur in isolation, but instead create 
situations where multiple factors contribute to an increased level of 
risk. (The Advocates, the EC, Public Citizen, TIA, Tire Rack, and ETRTO 
provided similar comments. In addition, ETRTO also called for testing 
at speeds below 31 mph.) VW/Audi recommended that the test procedures 
should incorporate a variety of speed ranges without the use of cruise 
control in order to be technology-neutral.
    Sumitomo recommended establishing a limit in the test procedures on 
longitudinal acceleration. Sumitomo argued that such a limit is 
necessary to reflect ordinary driving conditions, so the company 
recommended that longitudinal acceleration should be limited to  0.05 G during the calibration and low tire pressure detection 
phases.
    For the final rule, we have decided to adopt the test conditions as 
proposed in the NPRM. Commenters who requested a broader range of test 
speeds (both higher and lower) did not provide any evidence to show 
that the vehicle's TPMS would not function properly at vehicle speeds 
outside the 50-100 km/hr range. Furthermore, the commenters did not 
specify maximum or minimum test speeds that would ensure that real 
world driving conditions would be represented.
    Similarly, commenters who requested a broader range of ambient 
temperatures for testing (both higher and lower) did not provide any 
evidence to show that the vehicle's TPMS would not function properly at 
temperatures below 0[deg] C (32[deg] F) or above 40[deg] C (104[deg] 
F). We believe that this temperature range covers a large percentage of 
the temperatures normally encountered by most of the driving public in 
the United States. Furthermore, the commenters did not specify an 
ambient temperature range that they would consider to be more 
appropriate.
    We have decided not to include longitudinal acceleration limits in 
the test procedures for either system calibration or low tire pressure 
detection. It is our understanding that TPMS technology has improved 
since the time that the June 2002 final rule was published and that 
current systems detect and compensate for short periods of abnormal 
longitudinal acceleration. Accordingly, we do not believe that it is 
necessary to set longitudinal acceleration limits as part of the final 
rule.
    Regarding suggestions that compliance testing should be conducted 
on slippery road surfaces, commenters did not provide any evidence to 
show that the TPMS would not function normally on road surfaces with a 
coefficient of friction lower than the coefficient of friction of the 
road surface during compliance testing. Although surfaces with a lower 
coefficient of friction may result in increased wheel slip, which in 
turn could result in a slightly longer time to detect low tire 
pressure, we do not anticipate that additional safety benefits would 
arise from testing on slippery surfaces. Furthermore, the commenters 
did not specify a coefficient of friction or provide any other 
quantification for the recommended surface.
    We believe that the test conditions specified in this final rule 
will result in robust TPMSs that will function normally over a wide 
range of operating conditions. We do not believe that additional 
specifications related to temperature, weather, or speed would 
appreciably change the TPMS's performance or result in design changes 
yielding greater safety benefits.
    (c) MIL Activation. Under paragraph S6(l) of the proposed test 
procedures, the TPMS malfunction indicator would be tested by 
simulating one or more TPMS malfunction(s) by disconnecting the power 
source to any TPMS component, disconnecting any electrical connection 
between TPMS components, by simulating a TPMS sensor malfunction, or by 
installing a tire on the vehicle that is incompatible with the TPMS 
(S6(l)(1)). When the ignition locking system is turned to the ``On'' 
(``Run'') position (or, where appropriate,

[[Page 18168]]

the position for lamp check), the TPMS malfunction telltale would be 
required to illuminate (S6(l)(2)). The NPRM also proposed that for 
systems equipped a TPMS reset feature to extinguish the low tire 
pressure and/or malfunction telltale, the system would be reset in 
accordance with the manufacturer's instructions, after which, continued 
illumination of the MIL would be verified (S6(l)(3)). Finally, the 
proposal stated that the malfunction would be corrected, that the 
system would be reset (if necessary), and that there would be 
verification that the telltale has been extinguished (S6(l)(4)).
    Public comments on this issue relate to the previous discussion of 
what types of malfunctions the system should be required to detect and 
how quickly they should be detected. EnTire provided draft regulatory 
text for the portion of the standard's test procedures related to the 
TPMS malfunction indicator. The following paraphrases EnTire's 
recommended approach for the final rule on this issue. First, disable 
one of the following TPMS functions: (a) Control/transmission of 
information to the low pressure lamp; (b) transmission of pressure data 
from a sensor; or (c) capability of the controller to receive pressure 
information. Verify that the TPMS telltale(s) perform the check of lamp 
function. Drive for 15 minutes or until the malfunction lamp 
illuminates. If the MIL did not illuminate within that time period, 
reverse direction and drive for up to a total cumulative time of 20 
minutes or until the MIL illuminates. If the MIL does not illuminate, 
discontinue the test. If the MIL does illuminate, restore the system to 
normal operation. Drive for up to 15 minutes or until the malfunction 
lamp extinguishes. If the MIL did not extinguish within that time 
period, reverse direction and drive for up to a total cumulative time 
of 20 minutes.
    EnTire argued that this approach would resolve a number of 
questions which EnTire believes were left unanswered by the NPRM. 
According to EnTire, by focusing on the primary TPMS functions, it 
would clarify what malfunctions must be detected by the system. It 
would specify a time for the TPMS to discover the malfunction. It would 
specify that the vehicle is to be driven, because vehicular motion is 
necessary for many systems to run malfunction diagnostics. It would 
provide for verification of both the MIL lamp check and malfunction 
indication.
    EnTire also stated that because various malfunction conditions may 
require different recovery mechanisms to take place, the driving 
sequence for extinguishment may be avoided or reduced if the standard 
were to permit reference to additional instructions in the owner's 
manual procedures (if applicable).
    In its comments, NIRA Dynamics recommended that the final rule's 
test procedures should simulate a TPMS malfunction by disconnecting the 
power source to any TPMS component or by disconnecting any electrical 
connection between TPMS components, thereby limiting the requirements 
to only electrical and radio transmission errors. NIRA stated that the 
test procedures should be limited to detection of these types of 
malfunctions in order to keep the test procedures technology-neutral.
    Related to its earlier comments on the types of malfunctions that 
the system should be required to detect, Fuji commented that the 
proposed test procedures may involve disconnecting the power to the 
TPMS ECM, but that such action could make it impossible for the 
system's malfunction logic to operate.
    GM recommended adding 30 minutes of cumulative driving time for 
malfunction detection, under S6(l)(2) of the NPRM's proposed test 
procedures, in order to ensure that the TPMS has time to accumulate 
sufficient data to make a sound decision about whether a malfunction 
has occurred. The Alliance recommended a similar period of 30 minutes 
of continuous driving under S6(l)(4), in order to allow the TPMS the 
time necessary to confirm that a malfunction no longer exists.
    Fuji's comments made similar arguments, stating that in order to 
provide a reasonable battery life (8-10 years) for the wheel-mounted 
pressure sensors and transmitters, it and other vehicle manufacturers 
have designed their TPMSs to have the wheel sensors remain inactive 
until wheel rotation is above 40 kph. Fuji also commented that vehicle 
motion is required for the TPMS to begin its diagnostic cycle, along 
with a sufficient time period to make a reliable diagnosis of the 
malfunction. Accordingly, Fuji recommended that the final rule's test 
procedures include a drive time of at least 10 minutes with a vehicle 
speed of at least 40 kph.
    Nissan also commented that the test procedures related to 
malfunction detection should specify a time for detection and vehicle 
speed. Nissan recommended that the TPMS should be required to detect a 
malfunction under the same conditions and same timeframe as that 
required for detection of low tire pressure (i.e., within 10 minutes at 
speeds between 50 km/hr and 100 km/hr).
    In its comments, Schrader urged NHTSA to clarify its ``confusing'' 
test procedures related to TPMS malfunction detection. Schrader 
recommended that the TPMS test procedures should limit the simulation 
of a malfunction to removal of a component from the system.
    As noted above, the comments on the test procedures for the TPMS 
malfunction indicator intertwined substantive discussions of what types 
of malfunctions the system would be required to detect with procedural 
discussions of how the standard's test procedures would create those 
malfunctions and confirm that the TPMS can detect them. However, the 
substantive issue of what types of malfunctions the system must detect 
has been addressed in Section IV.C.2(b); that discussion will not be 
repeated here. Similarly, the time period for the TPMS to detect a 
system malfunction and to illuminate the MIL, was discussed in Section 
IV.C.2(a). For a complete discussion of those aspects of the test 
procedures, please consult those sections of this final rule.
    We recognize that most direct and indirect TPMSs will require that 
the vehicle be driven in order for the system to detect malfunctions. 
Commenters such as Nissan stated that most TPMSs use the same 
analytical processes for TPMS malfunction detection as they would for 
low tire pressure detection. Therefore, even though some commenters 
(e.g., Fuji, Nissan) suggested that malfunction detection would be 
possible for certain systems within a shorter timeframe, we have 
decided to adopt the same 20-minute driving time for TPMS malfunction 
detection as for the low tire pressure warning. In addition, we have 
incorporated the same test conditions (with some minor modification) as 
were proposed in S5 of the NPRM, including the requirement that the 
vehicle will be driven within a speed range of 50-100 km/hr, with no 
time accumulating when the service brake is applied. Again, we 
recognize that most TPMSs will require vehicular motion to detect that 
a TPMS malfunction has been corrected as well.
    Regarding EnTire's suggestion that there should be a specification 
for a MIL bulb check, such a requirement was already proposed in S6(b) 
of the NPRM, and it has been retained in this final rule. Further, we 
are not adopting EnTire's recommendation that the owner's manual be 
consulted for additional instructions related to operation of the MIL 
because we do not believe it is necessary. We believe that the final 
rule's requirements for MIL operation will provide a simple, 
consistent, and timely warning to the

[[Page 18169]]

driver in the event of a TPMS malfunction.
    (d) Vehicle Cool-Down Period. Under S6(e) of the NPRM, the vehicle 
would be stopped and kept stationary with the engine off for up to one 
hour, after which time one or more tires would be deflated to 7 kPa (1 
psi) below the level that should cause the TPMS low pressure warning 
telltale to illuminate. This provision would allow the tires time to 
cool prior to initiating the system detection phase of testing.
    In its comments, the Alliance recommended reducing the cool-down 
period in S6(e) from ``up to one hour'' to ``up to five minutes.'' The 
Alliance argued that, as currently proposed, this cool-down period 
could make the rule technology-dependent, because only direct TPMSs 
could comply. According to the Alliance's understanding, air would be 
let out of the vehicle's tire(s) after the cooling-down period, but 
some systems may not be able to detect the changes immediately, and by 
the time they can, the tires may have warmed up to a level above the 
warning threshold. However, the Alliance stated that if the test is 
conducted with tires that were under-inflated just after having been 
warmed up during the calibration phase, then those systems should be 
able to detect the differential.
    As a related matter, the Alliance argued that proposed S6(f)(3) of 
the NPRM, which provides instructions in the event that the TPMS low 
pressure telltale fails to illuminate after the tires are deflated and 
the vehicle is driven as required, should be revised to provide for an 
additional check of the tires' inflation pressures prior to 
discontinuing the test. The Alliance stated that it is requesting this 
change to avoid incorrect findings of noncompliance in cases where the 
tire inflation pressure is higher than the required TPMS activation 
threshold due to a tire temperature increase as a result of driving, 
ambient temperature changes, or a difference in temperature from the 
road surface in a stationary location to that of the test road surface. 
The Alliance recommended similar modifications to proposed paragraph 
S6(g).
    NIRA Dynamics made a similar comment, arguing that the portion of 
the NPRM's test procedures in which the tires are deflated could 
conceivably result in tires inflated above the warning threshold during 
the test. According to NIRA, tests have shown that tire pressure 
increases due to temperature changes after rapid deflation, which can 
negate the pressure change to some extent. Therefore, NIRA Dynamics 
recommended that the tire pressure be decreased to 2 psi below the 
warning threshold, and that if the TPMS does not issue a warning during 
the test, the tire pressure should be double-checked. Similarly, VW/
Audi recommended that the final rule should provide no more than five 
minutes to adjust and check the tires' inflation pressures before 
starting the system detection phase, and it supported decreasing the 
tire pressure to 2 psi below the warning threshold.
    Sumitomo stated that its experience has shown that it can take 
several minutes for the tire pressure to become stable after being set 
to a certain value. Thus, Sumitomo recommended that the test procedures 
be modified to set the tire 1 psi below the activation pressure, wait 
three minutes, and then verify the tire pressure to ensure that the 
pressure has been accurately set.
    In order to compensate for the temperature effects discussed by the 
Alliance, NIRA Dynamics, VW/Audi, and Sumitomo, we have decided to 
reduce the tire cool-down period in S6(e) from ``up to one hour'' to 
``up to five minutes,'' as requested by the commenters. We believe that 
the pressure differential between cold tire inflation pressure and 
running tire inflation pressure is approximately 8-10 percent. 
Therefore, tires that have their pressure reduced to the TPMS 
activation pressure while cold may experience a tire pressure increase 
once the vehicle has been driven for a short period of time, and this 
increase in pressure may prevent the TPMS from providing the low tire 
pressure warning.
    Regarding the commenters' recommendations for a decrease in the 
tire pressure deflation in S6(e) from the current 1 psi below the TPMS 
activation threshold to 2 psi below that level and for an additional 
pressure check, we have decided to adopt the 2 psi recommendation. We 
believe that this modification would be sufficient to account for the 
temperature effect described by the commenters without the need for 
additional pressure checks.
    (e) Testing with Pressures Other Than Placard Pressure. Under S6 of 
the NPRM, the proposed test procedures set placard pressure as the 
baseline for inflating and deflating tires during testing.
    The Alliance argued that because FMVSS No. 110 requires the new 
tire pressure label to specify only one recommended pressure, other 
recommended pressures for special conditions (e.g., extreme 
temperatures, heavy loads, off-road use) must now be provided in the 
owner's manual. Accordingly, the Alliance recommended revising the test 
procedures to provide that in conducting testing, NHTSA would consult 
the owner's manual and, if covered special conditions are present, use 
the inflation pressures specified for such conditions in lieu of the 
placard pressure. (Porsche and VW/Audi provided similar comments.) 
Schrader commented that TPMSs should accommodate drivers' needs to 
change inflation pressures to match the load on the tires.
    We are not adopting the commenters' recommendations regarding 
testing at pressures other than placard pressure, because we do not 
believe that any of the above-described ``special conditions'' are 
likely to occur during compliance testing.
    (f) System Reset. As reflected in the NPRM, the agency recognizes 
that many TPMSs are equipped with a system reset feature that must be 
used in appropriate circumstances. This understanding is reflected in 
the NPRM's test procedures, which refer to reset at S6(c), (i), (j), 
and (l).
    Several commenters discussed what they perceived to be an error in 
paragraph S6(i) of the test procedures, which discusses action to be 
taken at the end of the system detection phase (i.e., after point at 
which the low pressure telltale should have illuminated but prior to 
re-inflation of the tires). As proposed, that provision provided, ``If 
the vehicle's TPMS has a manual reset feature, attempt to reset the 
system in accordance with instructions specified in the vehicle owner's 
manual prior to re-inflating the vehicle's tires. If the low tire 
pressure telltale illuminates, discontinue the test.''
    The Alliance recommended elimination of S6(i) because it seems to 
imply that an owner may extinguish the TPMS low pressure telltale 
without correcting the under-inflation condition. According to the 
Alliance, manufacturers' recommended procedures for TPMS reset require 
that the manual reset procedure be performed only after correcting the 
inflation pressure. Continental Teves, Schrader, Sumitomo, and VW/Audi 
also raised this issue.
    Paragraph S6(c) of the NPRM proposed the following language, ``If 
applicable, reset the tire pressure monitoring system in accordance 
with the instructions in the vehicle owner's manual. The Alliance 
recommended modifying S6(c) to specify that the system will be ``set or 
reset.''
    BMW raised a more substantive argument regarding system reset, 
stating that a manufacturer should be permitted to incorporate a TPMS 
reset feature to accommodate situations such as a consumer switching 
between summer

[[Page 18170]]

and winter tires. According to BMW, the reset would allow the system to 
calibrate immediately after the tire change. BMW commented that if the 
agency is seriously concerned about driver misuse of a reset, NHTSA 
should consider a requirement that would prevent TPMS reset from the 
driver's seat.
    After further consideration on the issue of system reset, we have 
decided to delete the provision contained at S6(i) of the NPRM. Because 
some TPMSs cannot determine tire pressure in individual tires, these 
systems cannot detect correction of the under-inflation situation (and 
extinguish the low tire pressure telltale) without resetting the 
system. In light of the information presented by the commenters, we 
have decided not to test whether the TPMS telltale will extinguish 
after the system is reset. We expect that, for vehicles equipped with a 
reset, the owner's manual would have instructions for the proper use of 
the reset feature (e.g., stating that the driver should re-inflate the 
tires to the proper level before resetting the system).
    Regarding BMW's comment on the permissibility of a TPMS that may be 
reprogrammed or reset to accommodate different tires, we leave that 
decision to the vehicle manufacturer. As noted previously, NHTSA will 
conduct compliance testing with the tires installed on the vehicle at 
the time of initial sale.
    Regarding the Alliance's request to modify the language of S6(c), 
we have decided to adopt the Alliance's recommended language, although 
we believe that the Alliance's request largely involves semantics.
7. Lead Time and Phase-In
    The NPRM proposed the following schedule for compliance with the 
TPMS standard: 50 percent of a vehicle manufacturer's light vehicles 
would be required to comply with the standard during the first year 
(September 1, 2005 to August 31, 2006); 90 percent during the second 
year (September 1, 2006 to August 31, 2007); all light vehicles 
thereafter (see S7). The proposal stated that carry-forward credits 
would be provided for vehicles certified as complying with the standard 
that are produced after the effective date of the final rule.
    The NPRM's proposed schedule for lead time and phase-in was based 
upon information that the agency obtained from September 2003 Special 
Orders to 14 vehicle manufacturers (regarding their production plans 
for TPMS at the time of the Second Circuit's decision) and to 13 TPMS 
manufacturers (regarding their production capacity). From the responses 
to these Special Orders, NHTSA learned that, in anticipation of the 
start of the phase-in under the June 2002 final rule, most vehicle 
manufacturers were moving aggressively toward installation of TPMSs 
capable of meeting the four-tire, 25-percent under-inflation detection 
requirement, but some were not. The information provided by TPMS 
suppliers indicated sufficient capacity to supply TPMSs with a four-
tire, 25-percent detection capability in quantities that would easily 
meet the newly proposed phase-in requirements.
    In general, most of the vehicle manufacturers that commented on the 
NPRM, as well as the Alliance, requested additional lead time and a 
modified phase-in schedule. Public interest groups, such as the 
Advocates, expressed support for the NPRM's compliance schedule, as 
proposed. Specific comments and recommendations regarding lead time and 
the phase-in are discussed immediately below.
    (a) Lead Time. The Alliance recommended that the final rule include 
a two-year phase-in for compliance beginning on September 1, 2006. It 
stated that the agency could encourage early compliance by making 
phase-in credits available for compliant vehicles built after 
publication of the final rule. However, the Alliance made its lead time 
and phase-in recommendations contingent upon its assumption that the 
agency would defer the proposed MIL and related owner's manual 
provisions until September 1, 2007.
    The Alliance stated that the NPRM's prohibition against a telltale 
that changes color from yellow to red at increasingly low tire pressure 
levels will require manufacturers to add an additional telltale to the 
instrument panel. According to the Alliance, instrument panel redesign 
requires one to four years of lead time, so this change could not be 
accomplished before September 1, 2007.
    Similar comments about lead time were provided by AIAM, 
DaimlerChrysler, Fuji, GM, Hyundai, Porsche, Suzuki, VW/Audi, and 
Sumitomo. For example, the AIAM stated that the proposed MIL 
requirements could dictate redesign of vehicle dashboards and 
necessitate new software and hardware. AIAM also argued that changes to 
the owner's manual cannot be accomplished quickly, and that the owner's 
manuals for some MY 2006 vehicles have already gone to print. As a 
further example, Fuji argued that the proposed MIL requirements would 
necessitate substantial changes in ECM logic and circuitry, which will 
require additional design, calibration, testing, and incorporation by 
suppliers.
    The Alliance commented that, because of the need to lock in 
production-related decisions for MY 2006, if a final rule were issued 
later than December 2004, a phase-in beginning in September 2005 would 
only be feasible if the technical provisions of the new final rule 
would allow compliance certification for all systems currently in 
production that were designed in accordance with the carryover 
provisions of the June 5, 2002 final rule for TPMS, without any 
revision. (GM and the AIAM each made a similar comment.)
    The Alliance also stated that under the Safety Act, a Federal motor 
vehicle safety standard may not become effective in less than 180 
days.\50\ (The Alliance stated that its member companies will require 
the full 180 days in order to complete certification testing and 
documentation after the new standard is promulgated.) Therefore, the 
Alliance argued that, as a legal matter, March 1, 2005 is the latest 
date that the agency can issue a final rule and have it be effective on 
September 1, 2005. Once again, the Alliance commented that its 
statements regarding a September 2005 date for the start of compliance 
assumes deferral of compliance with the MIL provisions and related 
owner's manual language until September 1, 2007. (AIAM, BMW, Honda, 
Mitsubishi, Nissan, and Suzuki provided similar comments.)
---------------------------------------------------------------------------

    \50\ 49 U.S.C. 30111(d).
---------------------------------------------------------------------------

    The Alliance also commented that the agency should make FMVSS No. 
138 a test case for the proposed revisions to 49 CFR Part 568 that 
would allow final stage manufacturers and alterers, many of which are 
small businesses, an extra year for compliance.
    DaimlerChrysler commented that even if the agency were to publish a 
final rule in Spring 2005 that was identical to the September 2004 
NPRM, the company could not implement the MIL provisions in time for MY 
2006. DaimlerChrysler stated that close to two years is needed to 
convert an assembly plant in order to accommodate a TPMS component into 
the assembly line, and 9-12 months is needed to accommodate the newly 
proposed MIL requirement.
    In its comments, General Motors stated that it would require 24 
months from publication of a final rule to the effective date in order 
to meet the requirements of the new proposal. GM stated that this time 
period includes 18 months to engineer, prototype, tool, and

[[Page 18171]]

validate the system, and six months to go from vehicle validation test 
completion to production.
    Hyundai stated that NHTSA should extend the compliance date in the 
final rule to September 1, 2007, but dispense with the phase-in and 
instead require full compliance by that date.
    After careful consideration of the public comments related to lead 
time, we have decided to begin mandatory compliance (with a modified 
phase-in discussed below) on October 5, 2005, but to defer compliance 
with the standard's MIL requirements until September 1, 2007. The 
reasons for this decision are as follows.
    The proposed requirements for the TPMS to detect low tire pressure 
(i.e., a four-tire, 25-percent under-inflation detection capability) 
should have come as no surprise to vehicle manufacturers, because the 
Second Circuit's opinion in Public Citizen v. Mineta made clear that 
the standard would require a system with a four-tire detection 
capability, and the NPRM's proposed four-tire, 25-percent requirement 
harkened all the way back to the June 2002 final rule.
    The September 2004 NPRM also clearly indicated to the industry that 
NHTSA intended to specify requirements for TPMSs beginning with MY 
2006. Furthermore, vehicle manufacturers' own production data, as 
contained in the September 2003 Special Orders, demonstrated that at 
that time, the industry was well on its way in terms of planning for 
incorporation of TPMSs with a four-tire, 25-percent under-inflation 
detection capability.
    In addition, we do not agree with the Alliance's argument that 
additional lead time should be provided because manufacturers may wish 
to incorporate a second red lamp to indicate extremely low tire 
pressure; such a lamp is not required under the standard.
    However, we recognize that vehicle manufacturers could not be 
certain of the exact details of the final rule until publication of 
this notice. Therefore, in consideration of the changes made to this 
final rule (as described below, including deferral of the TPMS MIL 
requirements and associated owner's manual requirements), we have made 
adjustments to the percentages specified for light vehicle compliance 
with the phase-in in order to maintain Fall 2005 compliance date 
proposed in the NPRM. In an additional effort to maintain a Fall 2005 
compliance date, as further described below, we have decided to permit 
vehicle manufacturers to earn carry-forward credits and carry-backward 
credits (i.e., reduce compliance during the first year of the phase-in 
and increase compliance by a corresponding amount during the second 
year of the phase-in). We believe that these changes in the final rule 
effectively resolve manufacturers' lead time concerns. Consequently, we 
see no reason to delay implementation of the standard for an additional 
year in response to the arguments raised by the commenters.
    Regarding the TPMS MIL, we understand that the TPMS malfunction 
indicator represents a new requirement that was not present prior to 
the September 2004 NPRM, and that implementation of the MIL 
requirements may necessitate significant design and production changes 
(e.g., redesign of vehicle dashboards, new software and hardware). 
Therefore, it may not be practicable for vehicle manufacturers to 
comply with the TPMS MIL requirements by the start of the phase-in. We 
believe that the recommendation of at least 24 months lead time for the 
TPMS MIL is reasonable.
    In addition, as reflected in the Final Regulatory Impact Analysis 
for this rulemaking, the incremental benefits associated with the MIL 
are expected to be small in comparison to those provided by the 
system's low tire pressure warning. The TPMS MIL is expected to account 
for 0.677 percent of the final rule's estimated benefits, which equates 
to 1 fatality and 57 injuries prevented per year (see page VII-12 of 
the FRIA). Extrapolating from the figures provided in the FRIA, we 
believe that delaying the final rule until vehicle manufacturers could 
have a compliant TPMS MIL in place (i.e., delaying the 20-percent 
phase-in in MY 2006 and the 70-percent phase-in in MY 2007) would lead 
to an estimated 107 fatalities and 7,536 injuries that could have been 
prevented if TPMSs without an MIL were provided in vehicles under the 
final rule's phase-in (with benefits accruing over the life of vehicles 
so equipped). Accordingly, we believe that it would be more 
advantageous to have TPMSs (without an MIL) to begin being incorporated 
in new light vehicles sooner, rather than defer implementation of the 
entire standard. For these reasons, we believe that a compliance date 
of September 1, 2007 for the standard's MIL requirements (including 
associated owner's manual requirements) would be both practicable and 
maximize safety benefits under the standard.
    In response to the Alliance's comment that, by statute, a safety 
standard may not become effective less than 180 days after the standard 
is prescribed (see 49 U.S.C. 30111(d)), we have decided to postpone the 
start of compliance until 180 days after publication of this final 
rule. In order to better coincide with manufacturer production 
schedules, we have scheduled the second part of the phase-in to begin 
on September 1, 2006. However, if the agency is forced to postpone this 
compliance date for an additional year (i.e., eliminate the 20-percent 
compliance requirement for MY 2006), we would expect to lose 24 lives, 
a result that could be prevented if the vehicles subject to a phase-in 
commencing in Fall 2005 were equipped with a TPMS that could provide a 
low tire pressure warning to the driver. Such delay would also be 
expected to result in 1,675 more injuries than otherwise would have 
occurred.
    We believe that other changes between the June 2002 final rule and 
today's final rule for TPMS are relatively minor, and do not constitute 
major new and unexpected structural requirements. However, after 
considering public comments, we have sought to accommodate these 
changes through modifications in the phase-in schedule, as discussed in 
the next section below. Specifically, we have modified the compliance 
percentages of the phase-in, which should ease implementation.
    Furthermore, manufacturers have known since at least August 2003 
that a TPMS with a four-tire detection capability would be required and 
that there would likely be a requirement for 25-percent under-inflation 
detection. These expectations were confirmed in the September 2004 
NPRM, which included a proposed phase-in beginning September 1, 2005; 
manufacturers have not suggested that TPMS technologies are unavailable 
to meet those requirements. And once again we note that vehicle 
manufacturers' own production data, as contained their responses to the 
September 2003 Special Orders, demonstrated that at that time, most of 
the industry was moving aggressively in terms of planning for 
incorporation of TPMSs with a four-tire, 25-percent under-inflation 
detection capability. The Alliance's argument suggests that vehicle 
manufacturers have disregarded all of the knowledge they have gained 
about the eventual TPMS standard since the time of the Second Circuit's 
decision, including their own production plans.
    In addition, the Alliance has not provided any evidence to 
demonstrate that their members could not meet a Fall 2005 compliance 
date, other than to assert that they will require the full 180 days. 
The Alliance's comments also intimate that a September 1, 2005

[[Page 18172]]

phase-in would be feasible ``if the technical provisions of the new 
Final Rule allow compliance certification by all systems currently in 
production that were designed in accordance with the carryover 
provisions of the 2002 Final Rule, without any revision'' (which 
included a four-tire, 25-percent under-inflation detection option). 
Furthermore, we believe that concerns related to lead time are either 
rendered moot or significantly mitigated by the final rule's allowance 
of both carry-forward and carry-backward credits. For these reasons, we 
have decided to require compliance with the requirements of the 
standard beginning on October 5, 2005.
    In order to ease implementation, NHTSA has decided to permit 
vehicle manufacturers to earn carry-forward credits for compliant 
vehicles, produced in excess of the phase-in requirements, that are 
manufactured between the effective date of this rule and the conclusion 
of the phase-in.\51\ These carry-forward credits could be used during 
the phase-in, but they could not be used to delay compliance 
certification for vehicles produced at the conclusion of the phase-in. 
Except for vehicles produced by final-stage manufacturers and alterers 
(who receive an additional year for compliance), all covered vehicles 
must comply with FMVSS No. 138 on September 1, 2007, without use of any 
carry-forward credits.
---------------------------------------------------------------------------

    \51\ Any such certification of compliance with the standard is 
irrevocable.
---------------------------------------------------------------------------

    Furthermore, we have determined that there is good cause to make 
this final rule effective upon publication so that vehicle 
manufacturers would have a standard in effect to which they may certify 
vehicles for purposes of early, voluntary compliance and to maximize 
the time for earning carry-forward credits. Providing this earlier 
effective date may cause some vehicles to be equipped with TPMSs that 
otherwise might not have been, thereby advancing the safety goals of 
the standard. We explicitly note that vehicle manufacturers have no 
mandatory compliance responsibilities under the standard until the 
start of the phase-in.
    To further ease implementation and to maintain a Fall 2005 
compliance date, we have decided also to provide carry-backward 
credits, whereby vehicle manufacturers may defer compliance with a part 
or all of the certification requirements for the first period of the 
phase-in, provided that they certify a correspondingly increased number 
of vehicles under the standard during the second period of the phase-
in. Stated another way, carry-backward credits allow for under-
compliance in the first period of the phase-in, provided that there is 
corresponding, compensating over-compliance in the second period of the 
phase-in. For example, if a vehicle manufacturer anticipated production 
problems in terms of incorporating compliant TPMSs into vehicles 
produced from October 5, 2005, through August 31, 2006 (i.e., MY 2006), 
it could choose to certify 10 percent of its light vehicles to the 
standard during that period and commit to certifying 80 percent of its 
light vehicles manufactured from September 1, 2006 through August 31, 
2007 (i.e., MY 2007). We believe that permitting carry-backward credits 
would not impact the overall safety benefits of the final rule, because 
the same number of vehicles would be subject to compliance 
certification, although the distribution may vary over the model years 
of the phase-in. Corresponding changes have been added to the 
regulatory text of both FMVSS No. 138, as well as the TPMS phase-in 
requirements contained in 49 CFR Part 585.
    In addition, since the NPRM was published, NHTSA has issued a final 
rule pertaining to certification requirements for vehicles built in two 
or more stages and altered vehicles (see 70 FR 7414 (Feb. 14, 2005)). 
The amendments made in that final rule become effective September 1, 
2006. In relevant part, the multi-stage certification final rule 
amended 49 CFR 571.8, Effective Date, and it added a new subparagraph 
(b) providing as follows:

    (b) Vehicles built in two or more stages vehicles and altered 
vehicles. Unless Congress directs or the agency expressly determines 
that this paragraph does not apply, the date for manufacturer 
certification of compliance with any standard, or amendment to a 
standard, that is issued on or after September 1, 2006 is, insofar 
as its application to intermediate and final-stage manufacturers and 
alterers is concerned, one year after the last applicable date for 
manufacturer certification of compliance. Nothing in this provision 
shall be construed as prohibiting earlier compliance with the 
standard or amendment or as precluding NHTSA from extending a 
compliance effective date for intermediate and final-stage 
manufacturers and alterers by more than one year.

    In light of the agency's policy on multi-stage manufacturer 
certification, as expressed in the February 14, 2005 final rule, we 
have decided to adopt the Alliance's suggestion and to apply that 
principle to the compliance certification requirement for final-stage 
manufacturers and alterers under the TPMS standard. Thus, the final 
rule for TPMS is requiring final-stage manufacturers and alterers to 
certify compliance for all covered vehicles manufacturers on or after 
September 1, 2008. However, final-stage manufacturers and alterers may 
voluntarily certify compliance with the standard prior to this date 
(although no carry-forward credits would accrue in this case).
    (b) Phase-In Schedule. In their comments, vehicle manufacturers and 
the Alliance generally favored modification of the phase-in schedule 
set forth in the NPRM. The following summarizes the commenters' 
recommendations regarding the phase-in schedule. It should be noted 
that, unless otherwise indicated, the phase-in percentages specified 
below are exclusive of requirements related to the malfunction 
indicator, compliance with which manufacturers argued should be 
postponed until the end of the phase-in period.
    The Alliance recommended that 65 percent of covered vehicles should 
be required to comply in September 2006, and that 100 percent of 
covered vehicles should be required to comply in September 2007. The 
Alliance stated that this schedule would accommodate its member 
companies' different stages of readiness in terms of developing and 
producing large numbers of compliant TPMSs. The Alliance also argued 
that the agency has based its phase-in schedule on the responses to 
NHTSA's September 2003 TPMS Special Orders; however, the response to 
those Special Orders rested on certain vehicle manufacturer assumptions 
that have not proven true (e.g., that carry-forward credits would be 
available from the Fall of 2002, that indirect TPMSs could be used to 
comply with the rule). In addition, the Alliance commented that the MIL 
provisions are new to the NPRM and will require redesigns by 
manufacturers.
    In addition, Mitsubishi commented that business circumstances since 
the time of the Special Order have resulted in changes in product 
plans, which have impacted installation of TPMSs, and Mitsubishi stated 
that it uses different TPMS technology in each of its models, a factor 
which contributes to the need for longer lead time.
    AIAM recommended that 50 percent of covered vehicles should be 
required to comply in September 2006, and that 100 percent of covered 
vehicles should be required to comply in September 2007.
    BMW recommended that 35 percent of covered vehicles should be 
required to comply in September 2005, that 70 percent of covered 
vehicles should be

[[Page 18173]]

required to comply in September 2006, and that 100 percent of covered 
vehicles should be required to comply in September 2007.
    DaimlerChrysler recommended the following phase-in schedules if the 
proposed MIL are required at the start of the phase-in. If carry-
forward credits are permitted, DaimlerChrysler recommended that 70 
percent of covered vehicles should be required to comply in September 
2006, and that 100 percent of covered vehicles should be required to 
comply in September 2007. If carry-forward credits are not permitted, 
DaimlerChrysler recommended that 50 percent of covered vehicles should 
be required to comply in September 2006, and that 100 percent of 
covered vehicles should be required to comply in September 2007.
    If the MIL requirements are deferred to the end of the phase-in, 
DaimlerChrysler stated that it could support a recommendation that 30 
percent of covered vehicles should be required to comply in September 
2005, that 70 percent of covered vehicles should be required to comply 
in September 2006, and that 100 percent of covered vehicles should be 
required to comply in September 2007.
    Hyundai recommended that 100 percent of covered vehicles should be 
required to comply in September 2007, without any phase-in.
    Mitsubishi recommended that 50 percent of covered vehicles should 
be required to comply in September 2005, that 70 percent of covered 
vehicles should be required to comply in September 2006, and that 100 
percent of covered vehicles should be required to comply in September 
2007.
    Porsche recommended that 65 percent of covered vehicles should be 
required to comply in September 2006, and that 100 percent of covered 
vehicles should be required to comply in September 2007. Porsche stated 
that if a three-year phase-in is necessary, it recommended a 10-50-100% 
phase-in schedule, which is consistent with the June 2002 final rule.
    Fuji offered two recommended options for the phase-in. Under Option 
1, Fuji recommended that 50 percent of covered vehicles should be 
required to comply in September 2006, that 90 percent of covered 
vehicles should be required to comply in September 2007, and that 100 
percent of covered vehicles should be required to comply in September 
2008. Under Option 2, Fuji recommended that 100 percent of covered 
vehicles should be required to comply in September 2007, without any 
phase-in.
    VW/Audi recommended that 40 percent of covered vehicles should be 
required to comply in September 2006, and that 100 percent of covered 
vehicles should be required to comply in September 2007. VW/Audi's 
recommended schedule would include a MIL (consistent with its suggested 
changes). VW/Audi stated its belief that it would be preferable to 
postpone the phase-in until 2006 and require TPMSs with a MIL at that 
time, rather than begin the phase-in in 2005 and allow TPMSs without a 
MIL.
    After carefully considering all available information, we have 
decided to require a phase-in schedule for FMVSS No. 138 as follows: 20 
percent of a vehicle manufacturer's light vehicles must comply with the 
standard during the period from October 5, 2005, to August 31, 2006; 70 
percent during the period from September 1, 2006 to August 31, 2007, 
and all light vehicles thereafter. However, compliance with the 
standard's requirements for the TPMS malfunction indicator and related 
owner's manual language would be deferred until September 1, 2007, at 
which time those provisions also would be mandatory for all light 
vehicles.
    For the reasons discussed under the Lead Time section immediately 
above, we believe that this final rule, as modified, provides 
manufacturers with sufficient lead time to begin a October 5, 2005, 
phase-in of the core requirements of the TPMS standard (i.e., 
implementing the standard's low pressure detection requirements but 
briefly deferring implementation of the new requirements for the MIL 
and related owner's manual language). Once again, the requirements of 
the final rule are not drastically different from those of the 
(subsequently vacated) standard established by the June 2002 final 
rule, except for the deletion of the one-tire, 30-percent detection 
option and the addition of the MIL requirements. The Special Orders 
demonstrated that in Fall 2003, most vehicle manufacturers were moving 
aggressively towards TPMSs with a four-tire, 25-percent under-inflation 
detection capability and suppliers had sufficient capacity to meet 
demand. The direction of this rulemaking, in terms of a system with a 
four-tire, 25-percent detection capability, was again expressed in the 
September 2004 NPRM. In addition, some manufacturers (e.g., BMW, 
Mitsubishi) stated in their comments that they could begin 
certification to the standard in September 2005, provided that the MIL 
requirements and related owner's manual language requirements are 
deferred.
    However, based upon the information provided by the manufacturers 
and the rapidly approaching start of the 2006 Model Year, we have 
decided to modify the phase-in percentages from those contained in the 
NPRM. Particularly at this stage in a vehicle manufacturer's normal 
production cycle, a phase-in starting at 50 percent of production may 
not be practicable, so we have lowered that percentage to 20 percent. 
For similar reasons, we have also decided to modify the second year's 
phase-in percentage to 70 percent from 90 percent.
    Regarding the MIL requirements, vehicle manufacturers have 
commented that it would be possible to implement the necessary software 
and hardware changes fully by the conclusion of the phase-in on 
September 1, 2007. (No additional phase-in is being provided for the 
MIL requirements.) We believe that that timeframe is reasonable, in 
light of the technical and production challenges associated with 
incorporating the MIL. As a related matter, it would make little sense 
to include owner's manual language for the MIL until that feature is 
actually incorporated into the vehicle; therefore, the requirements for 
owner's manual language related to the MIL are similarly deferred until 
the conclusion of the phase-in.
    As a technical matter, we note that on December 8, 2004, NHTSA 
published a final rule that, among other things, consolidated the 
phase-in reporting requirements for various standards by revising 49 
CFR part 585 (69 FR 70904). The amendments in that final rule become 
effective on September 1, 2005. Accordingly, we have decided to make 
the TPMS final rule's amendments to part 585 for the TPMS phase-in 
reporting requirements effective that same day (i.e., September 1, 
2005). We do not anticipate that this delay in the effective date for 
the part 585 amendments will cause any problems, because not only does 
it coincide with the start of the TPMS phase-in, but also vehicle 
manufacturers are not expected to do any actual phase-in reporting 
until 2006. However, the details of the reporting requirements are 
available for recordkeeping purposes in the interim, something that may 
be of interest to manufacturers seeking carry forward credits for 
early, voluntary compliance.
8. Small Business Impacts
    In the NPRM, the agency tentatively concluded that the proposal 
would not have a significant economic impact upon a substantial number 
of small entities.

[[Page 18174]]

    SEMA's comments expressed disagreement with the NPRM's preliminary 
conclusion that the TPMS proposal would not have a significant economic 
impact upon a substantial number of small businesses. SEMA represents 
over 550 companies that manufacture, distribute, retail, and install 
tire, wheel, and tire/wheel accessories, most of which are defined as 
``small businesses.''
    Specifically, SEMA challenged the NPRM's contention that the 
proposal would not have a significant impact upon aftermarket wheel and 
rim manufacturers because the proposal does not contain requirements 
for spare tires and rims. SEMA argued that the proposal would indeed 
have an impact upon these manufacturers, because: (1) The NPRM would 
cover replacement tires and wheels installed by dealerships prior to 
first sale, and (2) the service industry would need to make sure that 
the malfunction telltale does not illuminate when one or more tires are 
replaced.
    According to SEMA, for replacement tires and wheels to work in 
conjunction with the OEM-installed TPMS, these aftermarket 
manufacturers may need to institute numerous and potentially costly 
changes, including equipment redesign, production retooling, and recall 
of noncompliant equipment. Furthermore, SEMA argued that the proposed 
TPMS standard could force small business installers of aftermarket 
wheel/tire combinations (e.g., automobile dealerships, tire shops, 
repair shops) to invest in computer diagnostic equipment and employee 
training in order to access, service, repair, install, and calibrate 
these TPMSs. Failure to take these steps could cause these businesses 
to violate the relevant statutory provisions prohibiting the 
manufacture/sale/importation of noncomplying motor vehicles \52\ and 
prohibiting actions that knowingly make inoperative safety devices and 
elements inoperative.\53\
---------------------------------------------------------------------------

    \52\ Under 49 U.S.C. 30112(a), ``* * * a person may not 
manufacture for sale, sell, offer for sale, introduce or deliver for 
introduction into interstate commerce, or import into the United 
States, any motor vehicle or motor vehicle equipment manufactured on 
or after the date an applicable motor vehicle safety standard 
prescribed under this chapter [49 U.S.C. 30101 et seq.] takes effect 
unless the vehicle or equipment complies with the standard and is 
covered by a certification issued under section 30115 of this 
title.''
    \53\ Under 49 U.S.C. 30122(b), ``A manufacturer, distributor, 
dealer, or motor vehicle repair business may not knowingly make 
inoperative any part of a device or element of design installed on 
or in a motor vehicle or motor vehicle equipment in compliance with 
an applicable motor vehicle safety standard prescribed under this 
chapter [49 U.S.C. 30101 et seq.] unless the manufacturer, 
distributor, dealer, or repair business reasonably believes the 
vehicle or equipment will not be used (except for testing or a 
similar purpose during maintenance or repair) when the device or 
element is inoperative.''
---------------------------------------------------------------------------

    In addition, SEMA stated that consumers would have legitimate 
expectations that the TPMS will continue to operate properly with 
replacement tires and wheels, and the aftermarket industry would be 
faced with product liability exposure.
    SEMA recommended that NHTSA consider alternative approaches, as 
outlined in its comments, in order to limit the impacts of the TPMS 
rule on the small business community. As discussed previously, SEMA 
recommended that vehicle manufacturers should be required to share with 
retailers, installers, and consumers, in a timely and affordable 
manner, all servicing information needed to operate a compliant TPMS. 
SEMA suggested that NHTSA consult with the Environmental Protection 
Agency (EPA) for guidance, because, according to SEMA, EPA has required 
vehicle manufacturers to share on-board diagnostic system (OBD) 
information with the service and repair industry in a timely and cost-
effective manner.
    SEMA's recommendations sought to ensure that manufacturers develop 
transparent and minimally burdensome processes for TPMS maintenance and 
repair. Specifically, SEMA commented that vehicle manufacturers should 
be required to comply with applicable Society of Automotive Engineers 
and European Union (EU) standards governing the design of wheel 
mounting pockets in order to facilitate transferal of sensors from the 
OE tires/wheels to replacement tires/wheels (no references provided). 
SEMA stated that communications protocols should be standardized so as 
to facilitate the use of aftermarket sensors, and that recalibration 
processes should be straightforward. SEMA also recommended that 
manufacturers should be prohibited from requiring special tools for 
TPMS reprogramming or utilizing encrypted systems that would prevent 
installation of aftermarket products.
    According to SEMA, if these changes are not adopted, the potential 
result would be to restrict aftermarket manufacturers from offering a 
full range of wheel and tire combinations to consumers, leaving such 
manufacturers with an unenviable choice between not selling these 
aftermarket products or accepting the associated product liability 
exposure.
    In contrast, VW/Audi stated that the test procedures in the final 
rule should recognize that some malfunctions may require action on the 
part of the dealer in order to extinguish the TPMS MIL.
    In the NPRM, the agency's rationale for its tentative conclusion 
that the proposal would not have a significant economic impact upon a 
substantial number of small entities was based upon several 
considerations. First, the agency understands that there are currently 
only four small motor vehicle manufacturers in the U.S. that would have 
to comply with the standard and that those manufacturers would rely on 
TPMS suppliers to provide the requisite system hardware to be 
integrated into their vehicles. There are a few small manufacturers of 
recreational vehicles, but the agency expressed its belief that most of 
these manufacturers could use the TPMSs supplied with the van chassis 
supplied by other large vehicle manufacturers and rely upon the chassis 
manufacturer's incomplete vehicle certification. We believe that the 
circumstances for these entities remain essentially unchanged.
    In the NPRM, the agency also sought to eliminate the concerns of 
small businesses that make and sell custom wheels and aftermarket rims 
by proposing to exempt spare tires and aftermarket rims (that do not 
match the original equipment rims) from the requirements of the 
standard on a practicability basis.
    For the following reasons, we continue to believe that the 
requirements of the standard, as contained in this final rule, will not 
have a significant economic impact upon a substantial number of small 
entities.
    We do not believe that the final rule will have a significant 
impact upon the service industry in terms of aftermarket sales or 
repair. First, the agency has already stated that we do not consider 
installation of an aftermarket or replacement tire or rim that is not 
compatible with the TPMS to be a ``make inoperative'' situation under 
49 U.S.C. 30122, provided that the business entity does not disable the 
TPMS MIL (see section IV.C.4(a)). In such situations, once the TPMS MIL 
illuminates, the consumer is put on notice that the aftermarket motor 
vehicle equipment in question is not compatible with the TPMS. From 
that point, it is within the consumer's power to substitute other tires 
or rims that permit continued proper TPMS functionality.
    In addition, SEMA has not provided any evidence to demonstrate that 
vehicle manufacturers would not make necessary repair and servicing 
information available to the aftermarket

[[Page 18175]]

sales industry and to the service industry. We have not received any 
consumer complaints regarding the serviceability of existing TPMSs. 
Vehicles currently include many complex systems, and, although dealer 
involvement may be necessitated in some cases, the marketplace has 
generally made available sufficient information to permit convenient 
maintenance and repair of such systems. We do not believe that TPMS 
technologies will prove any different in this regard. Accordingly, we 
believe that it is unnecessary to further consider SEMA's suggestion to 
compel vehicle manufacturers to share service information with the 
service and repair industry.
    We note that we are permitting, but not requiring, TPMSs to be 
reprogrammable. Although we are uncertain as to the exact details of 
system reprogrammability, we assume that it will be fairly easy for the 
service industry to reprogram TPMSs to accommodate different tires and 
rims. We do not have any reason to believe that such information would 
be withheld from automotive service providers.
    Regarding SEMA's suggestion that NHTSA require vehicle 
manufacturers to comply with SAE and EU standards governing the design 
of the wheel mounting pockets in order to facilitate transferal of 
sensors from the OE tires/wheels to replacement tires/wheels, we do not 
see a reason to impose such design restrictions on manufacturers.
    In addition, we believe that there are other available options for 
replacement of TPMS sensors without imposing such design restrictions. 
As we understand, there are two primary methods of mounting a direct 
TPMS sensor on a rim. The first option is to produce a mold for the rim 
that includes a small cut-out area for the TPMS sensor. The other 
option is to utilize a strap to hold the sensor to the rim. If 
aftermarket manufacturers do not receive specific information on the 
cut-out area or if they wish to produce a more generic mold that could 
be used on any vehicle with the same size tires, they could choose to 
use a strap to secure the TPMS sensor. We estimate that four straps 
might cost approximately $4, which is not very expensive as compared to 
the cost for replacement rims, so we believe that aftermarket rim 
suppliers could readily apply the strap method without a significant 
economic impact.
9. Environmental Impacts
    ETV commented that the final rule should include an expanded 
discussion of the rule's anticipated impacts on the environment. 
According to ETV, both positive and negative impacts would be expected 
to result from establishment of an FMVSS for TPMS. ETV stated that two 
important positive environmental benefits would be lower levels of air 
pollution and reduced tire disposal rates, both resulting from 
operating tires at their proper pressures. In its comments, ETV stated 
that correct tire pressure improves fuel economy, with less fuel burned 
and correspondingly less pollutants produced. Correct pressure also 
extends tire life, thereby decreasing tire disposal rates at waste 
depots.
    On the negative side, ETV stated that a significant environmental 
impact may result from the use of batteries to power wheel module 
pressure sensors in many TPMSs. The following summarizes ETV's view of 
these purported negative environmental impacts. According to ETV, there 
are approximately 16 million new vehicle produced annually that 
ultimately will be required to be equipped with a TPMS under the 
standard. If each vehicle has five tires (including the spare) fitted 
with battery-powered sensors, then there will be approximately 80 
million batteries introduced annually into the U.S. environment. 
Eventually, these batteries will lose their charge, and they (and the 
chemicals contained therein) will be discarded. ETV expressed concern 
that toxic and corrosive chemicals in those batteries could be released 
into the environment.
    According to ETV, in developing the final rule, NHTSA should 
carefully consider the impacts of requiring systems that will use 
chemical power sources, particularly given the standard's broad 
applicability. Instead, ETV argued in favor of a requirement for a 
batteryless TPMS, which ETV believes is practical, safe and 
economically viable.
    In the preamble to the NPRM, the agency certified that it has 
analyzed the TPMS rulemaking for the purposes of the National 
Environmental Policy Act (NEPA) and that the agency has determined that 
implementation of this action would not have any significant impact on 
the quality of the human environment. Even after having considered 
ETV's comments regarding the environmental impacts of our proposal, for 
the reasons that follow, we stand by our tentative conclusion that this 
action would not have any significant impact on the quality of the 
human environment.
    NHTSA has implemented the requirements of NEPA through our 
regulations at 49 CFR Part 520, Procedures for Considering 
Environmental Impacts. Our regulations require preparation of an 
environmental impact statement for ``major Federal actions 
significantly affecting the quality of the human environment.'' 49 CFR 
520.5(a). The regulations also provide specific examples of situations 
that should ordinarily be considered as significantly affecting the 
quality of the human environment. The relevant situations that might 
apply to the present rulemaking include:

    (8) Any action that may directly or indirectly result in a 
significant increase in the energy or fuel necessary to operate a 
motor vehicle, including but not limited to the following: (i) 
Actions which may directly or indirectly result in a significant 
increase in the weight of a motor vehicle; and (ii) actions which 
may directly or indirectly result in a significant adverse effect 
upon the aerodynamic drag of a motor vehicle;
    (9) Any action that may directly or indirectly result in a 
significant increase in the amount of harmful emissions resulting 
from the operation of a motor vehicle;
    (10) Any action that may directly or indirectly result in a 
significant increase in either the use of or the exposure to toxic 
or hazardous materials in the manufacture, operation, or disposal of 
motor vehicles or motor vehicle equipment;
    (11) Any action that may directly or indirectly result in a 
significant increase in the problem of solid waste, as in the 
disposal of motor vehicles or motor vehicle equipment;

49 CFR 520.5(b)(8), (9), (10), and (11).

    We believe that none of the purported impacts cited by ETV rise to 
the level of ``significantly affecting the quality of the human 
environment.'' According to ETV, a requirement for a TPMS would result 
in tires operating at proper pressures, thereby leading to lower levels 
of air pollution (through improved fuel economy) and reduced tire 
disposal rates (through increased tread life). As discussed in the 
FRIA, we believe that installation of a TPMS in light vehicles will 
result in an average savings of 22-27 gallons of gasoline over the life 
of the vehicle, depending upon the type installed. This equated to 
roughly two fill-ups, which would be expected to result in an average 
annual emissions reduction of 0.90-1.10 million metric cubic tons of 
carbon equivalent (see p. V-60 of the FRIA). While these benefits in 
terms of reduced emissions are welcome, they would not significantly 
change the overall level of emissions from automotive point sources. In 
addition, such positive impacts would not necessitate preparation of an 
environmental impact statement under our regulations pursuant to NEPA.

[[Page 18176]]

    Regarding increased tread life, we believe that installation of a 
TPMS will result in average tire tread life being increased by 740-900 
miles per tire, depending upon the type installed (see pp. V-61 to 67 
of the FRIA). The average lifespan of tires, at current inflation 
levels, is 45,000 miles. Consequently, although installation of a TPMS 
may increase the life of tires, it is unlikely to significantly impact 
the number of tires required over the life of the fleet or the number 
of tires ultimately reaching their final resting place in a landfill. 
However, any increases in tire life would be positive impacts that 
would not necessitate preparation of an environmental impact statement 
under our regulations pursuant to NEPA.
    Finally, we turn to the issue of the incorporation of chemical 
batteries in direct TPMSs that will eventually require disposal. 
NHTSA's current information suggests that most vehicle manufacturers 
will comply with the requirements of the TPMS standard by installing a 
direct TPMS that utilizes batteries in sensors mounted in each of the 
vehicle's wheels. If we expect, upon completion of the phase-in, 17 
million light vehicles would be certified to the standard each year, 
that would mean that 68 million batteries would be used. If 
manufacturers choose to also equip full-size spare tires with a TPMS 
sensor (15 percent anticipated), the number of batteries used would 
rise to 71 million.
    However, we do not believe that requiring TPMSs, which may be 
equipped with batteries, would have a significant impact on the quality 
of the human environment, as ETV suggests. To start, the number of 
batteries attributable to TPMSs would result in only a modest increase 
in the number of batteries sold. In 1998, the U.S. EPA estimated that 
approximately 3 billion \54\ industrial and household batteries were 
sold.
    NHTSA believes that battery usage is a function of population. 
Given that the population was roughly 270,248,000 \55\ in 1998 and 
293,028,000 \56\ in 2004, to arrive at a more current estimate, we 
proportionately increased the batteries sold by multiplying the 1998 
figure by the fractional increase in population or 3,000,000,000 x 
[293,028,000 270,248,000], which results in a 2004 estimate of 3.25 
billion batteries.
---------------------------------------------------------------------------

    \54\ See http://www.epa.gov/epaoswer/non-hw/reduce/epr/products/batteries.html.
    \55\ See http://www.census.gov/population/estimates/nation/intfile3-1.txt.
    \56\ See http://www.cia.gov/cia/publications/factbook/geos/us.html.
---------------------------------------------------------------------------

    Adding the estimate of 71 million additional batteries as a result 
of a battery-powered TPMS to the estimated 3.25 billion batteries 
already in use, yields an increase of 2.18 percent. We believe that 
this increase is not significant in terms of total battery use and will 
not have a significant impact upon the quality of the human 
environment.
    In addition, we believe that other considerations further diminish 
these impacts. First, TPMS sensor batteries tend to be extremely small 
in size, a mere fraction of the size of the main engine battery present 
in every vehicle. Thus, from a volume standpoint, these batteries would 
be expected to add very little to existing landfills, either in terms 
of their volume or chemical content.
    Furthermore, we believe that the number of batteries used in TPMSs 
is likely to decrease over time. We understand that new, batteryless 
TPMS technologies have been developed, and manufacturers will have 
strong incentives to migrate to such systems both in terms of 
decreasing costs and minimizing maintenance issues for customers. We 
also understand that indirect TPMSs are becoming available which can 
meet the requirements of the standard without the need for batteries. 
Furthermore, if hybrid systems are developed, the number of batteries 
for a given TPMS could be cut in half.
    For these reasons, we continue to believe that the TPMS rulemaking 
will not have any significant impact on the quality of the human 
environment.
10. Maintenance Issues
    (a) TPMS Maintenance. Aviation Upgrade Technologies commented that 
most consumers will not spend money to maintain the functionality of 
the TPMS, and it argued that because the system is unlikely to last the 
life of the vehicle without needing maintenance or repair, the safety 
benefits associated with the TPMS may be lost at some point. The 
commenter asserted that indirect TPMSs would need to be recalibrated 
each time tires are changed or rotated and that recalibration would 
cost the consumer $100 per episode.
    This comment does not comport with our understanding of how 
indirect TPMSs operate, and Aviation Upgrade Technologies was alone in 
making this point. It is our understanding from our review of indirect 
TPMSs that recalibration is a normal part of the system's operations 
after tires are changed or rotated, although it may be necessary to 
reset the system in accordance with instructions in the vehicle's 
owners manual. Furthermore, Aviation Upgrade Technologies did not 
provide any evidence, beyond its assertion, to demonstrate that the 
consumer would encounter such recalibration costs, nor did it provide 
any evidence to demonstrate the consumers would not be willing to incur 
routine maintenance costs associated with their vehicle's TPMS. We 
encourage consumers to keep their TPMS properly maintained in order to 
receive ongoing benefits in terms of low tire pressure warnings.
    (b) Tire Maintenance. In its comments, ETRTO expressed concern that 
installation of a TPMS in a vehicle may result in less preventive tire 
maintenance (e.g., regular pressure and wear checks) because drivers 
may rely upon the TPMS to inform them when tire service is necessary. 
(Similar comments were provided by NADA and SEMA.) According to the 
commenters, such a result would be contrary to the agency's goals 
related to tire safety.
    NADA argued that the NPRM did not adequately address the issue of 
whether TPMSs will necessitate tire installers/rotators to maintain 
existing rim positions and that it failed to analyze the nature and 
extent to which TPMS functions may be impacted when rims are replaced. 
NADA expressed concern that having to rotate tires off the rims could 
significantly increase the cost of tire rotations (which presumably 
could impact the regularity of rotations).
    Under the TREAD Act, Congress directed the Secretary of 
Transportation to promulgate a regulation to require installation of 
TPMSs in new motor vehicles, a responsibility that was subsequently 
delegated to NHTSA. As a result, NHTSA does not have discretion vis-
[agrave]-vis this TPMS mandate. However, NHTSA has stated many times 
that the TPMS is not a substitute for regular tire maintenance, and as 
part of this final rule, we have reiterated such a statement in the 
required owner's manual language.
    Although the presence of a TPMS in the vehicle may cause some 
drivers to become more complacent and to check their tire pressure less 
regularly, we believe that this potential, negative consequence would 
be outweighed by the positive impact of having the system provide a 
warning to all drivers, particularly those who seldom or never checked 
their tire pressure.
    Regarding NADA's comments on the potential consequences of allowing 
vehicle manufacturers to specify in the owner's manual that original 
rim positions must be maintained, we do not believe that this situation 
is likely to occur with significant frequency or that it would impose 
significant burdens when it does arise. For example, indirect TPMSs 
would not be expected to experience any problems associated with tire 
rotation.

[[Page 18177]]

    Several types of direct TPMSs have radio frequency receivers that 
identify sensors by their location on the vehicle. If the location of a 
particular sensor is changed, the sensor still will provide low tire 
pressure or TPMS malfunction data as designed when there is a general 
TPMS warning telltale. However, if the vehicle is equipped with a TPMS 
telltale that identifies the vehicle location of the tire with low 
pressure, tire and rim relocation (i.e., rotation) may result in the 
TPMS receiver not knowing the proper location of the tire/rim 
combination. However, for many systems, the sensors can be 
``retrained'' to their new positions on the vehicle after being 
rotated, and the telltale will identify the proper tire/rim position. 
Therefore, the tires on most TPMSs will not need to be separated from 
the rim for normal tire rotation as a result of this retraining 
capability.
    For these reasons, we have decided to adopt the proposed 
requirement for rim position under S5.3.3. Therefore, in conducting 
compliance testing, the vehicle rims may be positioned at any wheel 
position, consistent with any related instructions or limitations in 
the vehicle owner's manual.
11. Markings for Vehicles With Direct TPMSs
    SEMA recommended that NHTSA require a means of identifying vehicles 
equipped with a direct TPMS, so that individuals working in the service 
and repair industry will be able to tell whether a direct TPMS sensor 
is in place in or around the tires. According to SEMA, its suggestion 
may prevent damage to the TPMS sensors when the tires are dismounted or 
mounted. SEMA stated that such marking should be implemented in a 
manner that does not impose unnecessary burdens and costs on the tire 
and wheel industry, such as through permanent markings that would 
require retooling or new molds. Instead, SEMA suggested that one low-
cost option might be to require that vehicles equipped with a direct 
TPMS must have a unique, standardized valve stem retaining nut that is 
distinctive by special color or design.
    In its comments, TIA made similar arguments regarding the need to 
require coding of the wheels or tires to let automotive professionals 
know that a direct TPMS sensor is in place. TIA expressed support for 
the recommended approach contained in SEMA's comments. TIA also stated 
that TPMS sensor location should be standardized.
    We have decided not to adopt SEMA's and TIA's recommendations to 
require a specialized design feature to alert service and repair 
personnel when a direct TPMS sensor is in place in or around the tires, 
because we believe that such a requirement is unnecessary and would 
provide no safety benefit. The commenters did not provide any evidence 
to demonstrate that technicians have been unable to locate and service 
direct TPMSs currently installed on vehicles or that they would be 
unable to do so in the future. In contrast, we believe that as such 
systems become more prevalent in the vehicle fleet, service providers 
will become increasingly aware of the potential presence of TPMS 
sensors and will exercise due care when servicing the vehicle.
    We are not adopting TIA's recommendation that we mandate a specific 
location for TPMS sensors. We believe that such an approach would be 
unnecessarily design restrictive, could increase costs, and would 
provide no appreciable benefit.
12. Definitions
    (a) ``Tires''. Sumitomo commented that although the NPRM expressed 
the agency's intention to require vehicle manufacturers to assure 
compliance with FMVSS No. 138 only with the tires installed on the 
vehicle at the time of initial vehicle sale, there is no corresponding 
provision in the regulatory text of the standard. To address this 
matter, Sumitomo recommended that the final rule should incorporate 
this limitation under S1, Purpose and Scope, and also define the term 
``tires'' as ``the tires installed on the vehicle at the time of 
initial sale'' under S3, Definitions.
    Consistent with the preamble of the NPRM, this final rule provides 
that the TPMS must function properly with the tires installed on the 
vehicle at the time of initial sale, and that the TPMS is not required 
to function with the spare tire. We agree with Sumitomo that these 
topics should be addressed in the regulatory text. Therefore, we are 
adding a new paragraph to S5.3, Vehicle Conditions, related to tires. 
In that new paragraph, S5.3.7, Tires, we are clarifying that testing 
under S6 will be conducted with the tires installed at the time of 
initial vehicle sale, excluding the spare tire (if provided). However, 
a spare tire could be installed for TPMS malfunction testing purposes.
    (b) ``Manual Reset''. Sumitomo asked the agency to define the term 
``manual reset'' as ``an operation to extinguish the warning lamp or 
warning messages.'' According to Sumitomo, manual reset should not 
include the start of calibration.
    We do not believe that it is necessary to define the operation of a 
manual reset feature. In the final rule, we recognize that manual 
reset, where applicable, may be relevant to system calibration and 
extinguishment of the low tire pressure telltale, but we will leave the 
details of the operation of reset for individual systems to the 
discretion of vehicle manufacturers.
13. Educational Efforts
    A number of commenters (AAA, DaimlerChrysler, EnTire, VW/Audi) 
raised the issue of consumer education regarding the importance of 
proper tire maintenance and the role of the TPMS. For example, AAA 
recommended that NHTSA, manufacturers, and the traffic safety community 
must continue to aggressively educate motorists as to the importance of 
proper tire maintenance, in order to ensure that the presence of a TPMS 
does not lull motorists into a false sense of security.
    DaimlerChrysler commented that it is important for NHTSA, 
automobile manufacturers, and tire manufacturers to work together to 
educate the public about how TPMSs work and about such systems' 
limitations. DaimlerChrysler requested that the agency help improve 
consumer understanding of the importance of regular tire inspections 
and maintenance, and it suggested that NHTSA may be able to work with 
the vehicle supply and maintenance industries to improve the 
availability and convenience of facilities for checking and correcting 
tire inflation pressure levels.
    NADA stated that outreach efforts should be extended to tire 
installers as well.
    As noted in the NPRM, NHTSA supports industry efforts to make the 
public aware of the importance of proper tire maintenance, including 
maintaining adequate tire inflation pressure. The agency has produced a 
tire safety brochure in conjunction with tire manufacturers and tire 
dealers that is titled, ``Tire Safety, Everything Rides On It.'' This 
brochure is part of a public campaign to provide information on tire 
pressure monitoring, tire inspection, and the selection of replacement 
tires. The brochure also stresses the importance of tires to overall 
vehicle performance.
14. Alternative Systems
    Aviation Upgrade Technologies requested that NHTSA reconsider its 
tentative decision not to permit TPMS systems with indicators on a 
vehicle's tire valve stems. The NPRM declined to accommodate such 
systems because they cannot provide a low pressure warning to the 
driver while the vehicle is in motion.

[[Page 18178]]

    Aviation Upgrade Technologies argued that its valve cap system 
meets the letter and intent of the TREAD Act and actually outperforms 
other types of TPMSs by measuring actual tire pressure and functions 
before the vehicle begins moving. Aviation Upgrade Technologies also 
stated that as proposed, the TPMS standard would only benefit the 
wealthy, because the TPMSs that can meet the proposed requirements are 
expensive. The company's comments essentially repeat its earlier 
arguments raised in its petition for reconsideration of the June 2002 
final rule for TPMS.
    For the reasons expressed in the NPRM, we have decided not to 
permit TPMS systems with indicators on a vehicle's tire valve stems. We 
will briefly restate our reasoning, which is as follows. First, we 
believe that the language of and the safety need addressed by section 
13 of the TREAD Act would be best satisfied by requiring that the TPMS 
warning display be inside the motor vehicle in order to indicate to the 
driver when a tire is significantly under-inflated. We believe that 
external TPMS warning indicators do not provide a clear, timely, and 
effective safety warning, as compared to TPMS indicators in the 
vehicle's occupant compartment.
    Specifically, TPMSs with external indicators cannot provide a 
warning to the driver about low tire inflation pressure with the 
vehicle is in operation, which is the most critical time period from a 
safety perspective. If a vehicle developed a significant pressure loss 
while it is being driven, the driver would not receive a prompt warning 
from a valve stem system and is unlikely to be aware of the under-
inflation problem.
    Even in cases in which the vehicle is stopped, we believe that 
external TPMS warning indicators would not provide as effective a 
warning as a TPMS telltale inside the occupant compartment. People 
routinely do not walk around their vehicle prior to driving, so it is 
likely that many drivers would miss the message provided when there is 
an under-inflated tire. Therefore, we believe that valve cap devices 
would not provide an adequate warning to the driver.
    Second, NHTSA also finds benefit to the centralization of warning 
indicators in a single, highly visible location, where they can provide 
important safety-related information to the driver. Historically, NHTSA 
has required safety warnings to be provided to the vehicle operator 
inside the vehicle.
    Therefore, we have decided not to accommodate TPMSs that do not 
include an on-board telltale as part of the final rule.
15. Over-Inflation Detection
    ETV commented that, although requiring the TPMS to monitor high 
pressure is as important as monitoring low pressure, the NPRM did not 
consider or address this issue. ETV stated that manufacturers specify a 
safe maximum tire pressure, and that the final rule should address this 
aspect of vehicle safety. ETV's comments recommended an intermittently 
flashing yellow telltale warning when the vehicle's tires are within 
five percent of their maximum inflation pressure and an intermittently 
flashing red telltale when the vehicle's tires have exceeded the 
maximum inflation pressure.
    We have decided not to adopt a requirement for over-inflation 
detection for the following reasons. First, the TREAD required a 
rulemaking to detect a significantly under-inflated tire, not over-
inflated tires, so such a requirement is arguably outside the scope of 
this rulemaking. Furthermore, we are not aware of vehicle safety data 
reporting over-inflated tires as a significant safety hazard. In 
addition, available information does not suggest that over-inflation 
has the same safety implications as under-inflation, which causes heat 
buildup in a tire, potentially leading to permanent tire damage and 
sudden failure.
16. Temperature and Altitude Compensation
    ETV requested that the agency reconsider its tentative decision in 
the NPRM to not include a requirement for temperature compensation as 
part of the TPMS standard. ETV argued that the standard must provide 
temperature compensation when the TPMS calculates tire pressure in 
order to determine the need for activation of the low pressure warning. 
According to ETV, temperature compensation is needed to account for the 
rise in pressure (4 psi) from the cold-start, ambient temperature to 
the normal running temperature.
    ETV also stated that the TPMS should be required to account for 
changes in atmospheric pressure that accompany changing altitudes. ETV 
commented that such atmospheric pressure changes could change tire 
pressure by as much as 10 psi.
    ETV argued that the TPMS should make the necessary adjustments to 
account for temperature, altitude, and load prior to vehicle motion in 
order to prevent nuisance warnings that may result from daily and 
seasonal variations in those factors and which eventually might cause 
the driver to ignore TPMS warnings. Alternatively, ETV argued that 
those factors could cause the TPMS low pressure telltale to fail to 
illuminate, thereby resulting in a false sense of security on the part 
of the driver.
    We have decided not to adopt requirements for temperature and 
altitude compensation because we believe that such requirements would 
introduce unnecessary complexity to the standard. Regarding temperature 
correction, the test procedures for low tire pressure detection in the 
final rule have been amended to compensate for tire pressure 
fluctuation. Tires will be deflated to testing pressure within five 
minutes after a 20-minute period of driving, which will ensure that the 
tire pressure will not rise above the telltale activation pressure 
during the remainder of the test.
    Regarding altitude correction, we do not believe that altitude will 
be a significant factor in tire pressure fluctuation. We expect that 
the effect of atmospheric pressure on tire pressure will not result in 
more than a 5-percent change in tire pressure over the atmospheric 
pressure extremes encountered during normal driving.
    We note further that ETV did not provide any data to demonstrate 
the need for either temperature or atmospheric compensation.
17. System Longevity
    ETV commented that the TPMS safety system should be required to 
last for the life of the vehicle, which ETV stated is usually about ten 
years. ETV's comments expressed particular skepticism toward battery-
dependent TPMSs, which it suggests are likely to fail in under ten 
years, and it argued that consumers may decide not to replace the 
batteries or otherwise repair the system late in the life of the 
vehicle. ETV argued that operation of the vehicle in that state would 
frustrate the purpose of the rule.
    We are not adopting ETV's suggestion for what amounts to a 
longevity requirement for the vehicle's TPMS, because we believe that 
such a requirement is both impracticable and unnecessary. Vehicle 
systems and components routinely wear out over the life of a vehicle, 
although the frequency may vary. For example, drivers may need to 
replace their wiper blades several times over the life of the vehicle, 
to replace their timing belt once, but perhaps never need to replace 
their transmission. It is simply not reasonable to expect vehicle 
manufacturers to certify that a system, such as the TPMS, will function 
for the life of the vehicle.

[[Page 18179]]

Instead, we believe that consumer expectations and market competition 
will ensure that manufacturers provide TPMSs that are reasonably 
robust.
    Furthermore, ETV has provided no evidence to demonstrate that 
consumers would not take the necessary steps to keep their TPMS 
functioning (even for systems with battery-powered sensors) or that the 
service industry would be unable to provide adequate TPMS repair.
18. Harmonization
    The EC commented that the United Nations (UN) World Forum on 
Harmonization of Motor Vehicle Regulations has begun a global technical 
regulation (GTR) on tires. Accordingly, the EC requested that the 
United States adapt TPMS requirements in the future to reflect the work 
of this international body.
    NHTSA will follow closely international efforts related to tires 
and TPMSs, including the activities of the UN World Forum on 
Harmonization of Motor Vehicle Regulations. To the extent that a GTR or 
a consensus standard related to TPMS becomes available, the agency will 
carefully consider what actions, if any, are necessary to amend FMVSS 
No. 138.

V. Benefits

    In preparing its June 5, 2002 final rule, NHTSA prepared a Final 
Economic Analysis (FEA), which was placed in the docket.\57\ In that 
document, we discussed the costs and benefits of both the four-tire, 
25-percent option and the one-tire, 30-percent option incorporated in 
that final rule. However, in Public Citizen, Inc. v. Mineta, the Second 
Circuit determined that the TREAD Act requires TPMSs to be four-tire 
systems and invalidated the one-tire, 30-percent option. Accordingly, 
that option has not been included in this final rule.
---------------------------------------------------------------------------

    \57\ Docket No. NHTSA-2000-8572-216.
---------------------------------------------------------------------------

    Although the FEA included analyses related to TPMSs with a four-
tire, 25-percent under-inflation detection capability (the same 
performance standard required in this final rule), circumstances have 
changed to a certain extent since the June 2002 final rule. New 
technologies are emerging (e.g., batteryless direct TPMSs that could 
greatly reduce maintenance costs for such systems), and new 
requirements have been adopted (e.g., requirement for a TPMS 
malfunction indicator). Accordingly, the agency has prepared a new 
Final Regulatory Impact Analysis to accompany this final rule for tire 
pressure monitoring systems. The FRIA has been submitted to the Docket 
under the docket number for this notice.
    The purpose of the FRIA is to reassess the costs and benefits of 
TPMS requirements, particularly in light of our resolution of the 
replacement tire issue and the requirement for a TPMS malfunction 
indicator. (The FRIA states that incorporation of a TPMS malfunction 
indicator may save an additional two equivalent lives, assuming a one-
percent malfunction rate for replacement tires.) In addition, the FRIA 
examines various technologies suitable for compliance with the 
standard, as well as additional regulatory alternatives considered by 
the agency. It also discusses the uncertainties analyses and 
sensitivities analyses conducted by the agency as part of the FRIA, as 
required by OMB Circular A-4, Regulatory Analysis, which was issued in 
September 2003.
    The following discussion summarizes the benefits associated with 
this final rule and its four-tire, 25-percent under-inflation detection 
requirement. Estimates of monetary impact (both in the section V. 
Benefits and section VI. Costs) are presented using a 3-percent 
discount rate; however, the FRIA also presents these impacts using a 7-
percent discount rate.
    The agency notes that the FRIA estimates 90-percent confidence 
bounds for many of the benefit and cost statistics. Those bounds 
reflect a 90-percent certainty level that the value is within that 
range (both for a 3-percent and a 7-percent discount rate). However, to 
simplify the discussion here, we are presenting the mean values for the 
benefit estimates in this section and the cost estimates in the next 
section, with the ranges below reflecting differences in the mean 
values based upon manufacturers' technology selection. The mean values 
are our best estimates. Please consult the FRIA for a more complete 
discussion of benefits and costs. The full ranges of benefits and 
costs, as well as their 90-percent confidence bounds, can be found in 
the FRIA's uncertainty analysis (Chapter X).
    Under-inflation of tires affects the likelihood of many different 
types of crashes. These include crashes which result from: (1) Skidding 
and/or losing control of the vehicle in a curve, such as a highway off-
ramp, or in a lane-change maneuver; (2) hydroplaning on a wet surface, 
which can cause increases in stopping distance and skidding or loss of 
control; (3) increases in stopping distance; (4) flat tires and 
blowouts, and (5) overloading the vehicle. In assessing the impact of 
this final rule on those crashes, the agency assumes that 90 percent of 
drivers will respond to a low tire pressure warning by re-inflating 
their tires to the recommended placard pressure.
    Based upon this assumption and depending upon the specific 
technology chosen for compliance, the agency estimates that the total 
quantified safety benefits from reductions in crashes due to skidding/
loss of control, stopping distance, and flat tires and blowouts will be 
119-121 fatalities prevented and 8,373-8,568 injuries prevented or 
reduced in severity each year, if all light vehicles meet the TPMS 
requirement.
    Further, NHTSA anticipates additional economic benefits from the 
standard due to improved fuel economy, longer tread life, property 
damage savings, and travel delay savings. Correct tire pressure 
improves a vehicle's fuel economy. Based upon data provided by 
Goodyear, we have determined that a vehicle's fuel efficiency is 
reduced by one percent for every 2.96 psi that its tires are below the 
placard pressure. The agency estimates that if all light vehicles meet 
the TPMS requirement, vehicles' higher fuel economy would translate 
into an average discounted value of $19.07-$23.08 per vehicle over the 
lifetime of the vehicle, depending upon the specific technology chosen 
for compliance.
    Correct tire pressure also increases a tire's tread life. Data from 
Goodyear indicate that, for every 1-psi drop in tire pressure, tread 
life decreases by 1.78 percent. NHTSA estimates that if all light 
vehicles meet the four-tire, 25-percent compliance requirement, average 
tread life would increase by 740 to 900 miles. The agency estimates 
that the average discounted value of resulting delays in new tire 
purchases would be $3.42-$4.24 per vehicle, depending upon the specific 
technology chosen for compliance.
    To the extent that TPMSs provide improvements related to stopping 
distance, blowouts, and loss of control in skidding, we expect that 
some crashes would be prevented and that in others, the severity of the 
impacts and the injuries that result would be reduced. As a related 
matter, we expect that property damage and travel delays would also be 
mitigated by these improvements. To the extent that crashes are 
avoided, both property damage and travel delay would be completely 
eliminated. Crashes that still occur, but do so at less serious impact 
speeds, would still cause property damage and delay other motorists, 
but to a lesser extent than they otherwise would have. The value of 
property damage and travel delay savings is

[[Page 18180]]

estimated to be from $7.70-$7.79 per vehicle.

VI. Costs

    The FRIA also contains an in-depth analysis of the costs associated 
with the TPMS standard. It analyzes the cost of different TPMS 
technologies, overall vehicle costs, maintenance costs, testing costs, 
and opportunity costs. The FRIA also analyzes the cost impact of the 
requirement for a TPMS malfunction warning and its effectiveness in 
resolving the replacement tire issue.\58\ Again, please consult the 
FRIA for a more complete discussion of costs.\59\ The following points 
summarize the key determinations related to costs.
---------------------------------------------------------------------------

    \58\ As noted in the discussion of benefits in the section 
immediately above, the following discussion of costs estimates 
monetary impacts using a 3-percent discount rate and provides the 
mean values for cost statistics based upon manufacturers' technology 
selection. The mean values are our best estimates. However, the FRIA 
provides a full range of costs, as well as their 90-percent 
confidence bounds, and it also presents these impacts using a 7-
percent discount rate.
    \59\ With future technological development, it may become 
possible for indirect TPMSs and other types of systems to meet the 
four-tire, 25-percent requirement. However, until such new, 
compliant TPMSs are developed, it is impossible to accurately 
estimate their costs.
---------------------------------------------------------------------------

    The agency examined three types of technology that manufacturers 
could use to meet the TPMS requirements. Assuming that manufacturers 
will seek to minimize compliance costs, the agency expects that 
manufacturers would install hybrid TPMSs on the 67 percent of vehicles 
that are currently equipped with an ABS and direct TPMSs on the 33 
percent of vehicles that are not so equipped. The highest costs for 
compliance would result if a manufacturer installed direct TPMSs with 
an interactive readout of individual tire pressures that included 
sensors on all vehicle wheels.
    In the near term, the agency believes that a direct system with a 
generic warning lamp (Option 2) is the most likely option to be 
selected by automobile manufacturers. To date, no one has produced a 
hybrid system (Option 3) and responses to requests for information from 
the manufacturers resulted in most indicating that they were planning 
on using direct systems. Individual tire pressure displays (Option 1) 
are more costly than a warning light and are not required by the final 
rule, but some manufacturers may choose them for their higher priced 
models. In the long run, the agency suspects that price pressure and 
further development of tire pressure monitoring systems could result in 
hybrid or indirect systems meeting the final rule and being introduced.
    Thus, the agency estimates that the average incremental cost for 
all vehicles to meet the standard's requirements would range from 
$48.44-$69.89 per vehicle, depending upon the specific technology 
chosen for compliance. Since approximately 17 million vehicles are 
produced for sale in the U.S. each year, the total annual vehicle cost 
is expected to range from approximately $823-$1,188 million per year.
    The agency estimates that the net cost per vehicle [vehicle cost + 
maintenance costs + opportunity costs--(fuel savings + tread life 
savings + property damage and travel delay savings)] would be $26.63-
$100.25, assuming a one-percent TPMS malfunction rate for replacement 
tires. (Maintenance costs would be variable, depending upon whether the 
TPMS has batteries or is batteryless.) As noted above, the agency 
estimates the total annual vehicle cost for the fleet would be about 
$823-$1,188 million. Thus, using the same equation, the agency 
estimates the total annual net cost would be about $453-$1,704 million.
    NHTSA estimates that the net cost per equivalent life saved would 
be approximately $2.3-$8.5 million, depending upon the specific 
technology chosen for compliance. Placing 90-percent confidence bounds 
around the cost per equivalent life saved results in a range of $1.5-
$14.5 million.
    Net benefits-costs (i.e., benefits, including fatalities and 
injuries, valued in dollars minus costs) were also calculated per OMB 
Circular A-4. The value of a statistical life is uncertain, and a wide 
range of values has been established in the literature. (In general, 
the statistical value of a life is valued in the range of $1 million to 
$10 million per life, with a midpoint of $5.5 million.) For this 
analysis, we have examined values of $3.5 million and $5.5 million, 
both of which fall within the range of accepted values. The mean value 
for net benefits-costs ranges of the TPMS standard from a net cost of 
$597 million to a net benefit of $655 million, depending upon the 
specific technology chosen for compliance. A 90-percent confidence 
bound around the net benefits-costs results in a range from a net cost 
of $1,156 million to a net benefit of $1,302 million.

VII. Regulatory Alternatives

    The performance requirements specified in this final rule contain 
two key variables: (1) The number of tires monitored and (2) the 
threshold level for providing tire pressure warnings. As noted 
elsewhere in this preamble, the Second Circuit determined in Public 
Citizen, Inc. v. Mineta that the TREAD Act unambiguously mandates TPMSs 
capable of monitoring each tire up to a total of four tires, 
effectively precluding any option with less than a four-tire detection 
capability. Further, the Court found that the agency had justification 
for adopting a four-tire, 25-percent option instead of the four-tire, 
20-percent option proposed at an earlier stage of the rulemaking.
    Although NHTSA is requiring a 25 percent below placard threshold 
for under-inflation detection, technically, other threshold levels 
could also be established. Selecting an appropriate notification 
threshold level is a matter of balancing the safety benefits achieved 
by alerting consumers to low tire pressure against over-alerting them 
to the point of becoming a nuisance and causing consumers to ignore the 
warning, thus negating the potential of the standard to produce safety 
benefits. Degradation in vehicle braking and handling performance does 
not become a significant safety issue at small pressure losses. There 
does not appear to be a specific threshold level at which benefits are 
maximized by a combination of minimum reduction in placard pressure and 
maximum response by drivers. NHTSA is confident that existing 
technology can meet the 25 percent threshold.
    Setting a lower threshold might have resulted in the opportunity 
for more savings if drivers' response levels were maintained; however, 
we are concerned that setting a lower threshold could result in a 
higher rate of non-response by drivers who regard the more frequent 
notifications as a nuisance. Current direct TPMS systems have a margin 
of error of 1-2 psi. That means, for example, that for a 30-psi tire, 
manufacturers would have to set the system to provide a warning when 
tires are 4 psi below placard if we had decided to require a 20 percent 
threshold. We have concluded that this may be approaching a level at 
which a portion of the driving public would begin to regard the warning 
as a nuisance. We have not examined lower threshold levels in this 
analysis because we believe that the net impact of these offsetting 
factors (quicker notification, but lower frequency of driver response) 
is unknown and unlikely to produce a significant difference in safety 
benefits. We note that a four-tire, 20-percent option was examined in 
our March 2002 analysis, and that the total benefit for the 20 percent 
threshold was about 15 percent higher than from the 25 percent 
threshold. However, that calculation assumed the same level of driver 
response for both thresholds. It is also possible that lower thresholds 
might

[[Page 18181]]

limit technology and discourage innovation.
    Overall, we have concluded that the 25 percent threshold adequately 
captures the circumstances at which low tire pressure becomes a safety 
issue. We also believe that this level would be acceptable to most 
drivers and would not be considered a nuisance to the point that it 
would be ignored by large numbers of drivers. We also believe there is 
no reason to examine higher thresholds (e.g., a 30 percent threshold), 
since they would provide fewer benefits for similar costs.

VIII. Rulemaking Analyses and Notices

A. Vehicle Safety Act

    Under 49 U.S.C. Chapter 301, Motor Vehicle Safety (49 U.S.C. 30101 
et seq.), the Secretary of Transportation is responsible for 
prescribing motor vehicle safety standards that are practicable, meet 
the need for motor vehicle safety, and are stated in objective 
terms.\60\ These motor vehicle safety standards set a minimum standard 
for motor vehicle or motor vehicle equipment performance.\61\ When 
prescribing such standards, the Secretary must consider all relevant, 
available motor vehicle safety information.\62\ The Secretary also must 
consider whether a proposed standard is reasonable, practicable, and 
appropriate for the type of motor vehicle or motor vehicle equipment 
for which it is prescribed and the extent to which the standard will 
further the statutory purpose of reducing traffic accidents and 
associated deaths.\63\ The responsibility for promulgation of Federal 
motor vehicle safety standards has been delegated to NHTSA.\64\
---------------------------------------------------------------------------

    \60\ 49 U.S.C. 30111(a).
    \61\ 49 U.S.C. 30102(a)(9).
    \62\ 49 U.S.C. 30111(b).
    \63\ Id.
    \64\ 49 U.S.C. 105 and 322; delegation of authority at 49 CFR 
1.50.
---------------------------------------------------------------------------

    As noted previously, section 13 of the TREAD Act mandated a 
regulation to require a tire pressure monitoring system in new 
vehicles. In developing this final rule for TPMS, the agency carefully 
considered the statutory requirements of both the TREAD Act and 49 
U.S.C. Chapter 301.
    First, this proposal is preceded by an initial NPRM, a final rule, 
and a second NPRM, all of which facilitated the efforts of the agency 
to obtain and consider relevant motor vehicle safety information, as 
well as public comments. Further, in preparing this document, the 
agency carefully evaluated available research, testing results, and 
other information related to various TPMS technologies. We have also 
updated our cost and benefit analyses to account for new technologies 
emerging since issuance of our prior notices in the ongoing TPMS 
rulemaking (e.g., batteryless direct TPMSs). In sum, this document 
reflects our consideration of all relevant, available motor vehicle 
safety information.
    Second, to ensure that the TPMS requirements are practicable, the 
agency considered the cost, availability, and suitability of various 
TPMSs, consistent with our safety objectives and the requirements of 
the TREAD Act. We note that TPMSs are already installed on many light 
vehicles, so we believe that it will be practicable to extend a TPMS 
requirement to all light vehicles. In light of the steady advances made 
in TPMS technologies over the past few years, we expect that vehicle 
manufacturers soon will have a number of technological choices 
available for meeting the requirements of the final rule for TPMS. In 
sum, we believe that this final rule is practicable and will provide 
several benefits, including prevention of deaths and injuries 
associated with significantly under-inflated tires, increased tread 
life, fuel economy savings, and savings associated with avoidance of 
property damage and travel delays (i.e., from crashes prevented by the 
TPMS).
    Third, the regulatory text following this preamble is stated in 
objective terms in order to specify precisely what performance is 
required and how performance will be tested to ensure compliance with 
the standard. Specifically, the final rule sets forth performance 
requirements for operation of the TPMS, both in terms of detecting and 
providing warnings related to low tire pressure and system malfunction.
    The final rule also includes test requirements for TPMS 
calibration, low tire pressure detection, and TPMS malfunction. This 
test involves driving the vehicle under a defined set of test 
conditions (e.g., ambient temperature, road test surface, test weight, 
vehicle speed, rim position, brake pedal application) on a designated 
road course in San Angelo, Texas. The test course has been used for 
several years by NHTSA and the tire industry for uniform tire quality 
grading testing. The standard's test procedures carefully delineate how 
testing will be conducted. Thus, the agency believes that this test 
procedure is sufficiently objective and would not result in any 
uncertainty as to whether a given vehicle satisfies the requirements of 
the TPMS standard.
    Fourth, we believe that this final rule will meet the need for 
motor vehicle safety because the TPMS standard will provide a warning 
to the driver when one or more tires become significantly under-
inflated, thereby permitting the driver to take corrective action in a 
timely fashion and potentially averting crash-related injuries. 
Furthermore, by including a requirement for a TPMS malfunction 
indicator, we expect that the TPMS will be able to continue to provide 
low tire pressure warnings even after the vehicle's original tires are 
replaced. The TPMS malfunction indicator will also alert the consumer 
as to when the system is unavailable to detect low tire pressure and is 
potentially in need of repair.
    Finally, we believe that this final rule is reasonable and 
appropriate for motor vehicles subject to the applicable requirements. 
As discussed elsewhere in this notice, the agency is addressing 
Congress' concern that significantly under-inflated tires could lead to 
tire failures resulting in fatalities and serious injuries. Under the 
TREAD Act, Congress mandated installation of a system in new vehicles 
to alert the driver when a tire is significantly under-inflated, and 
NHTSA has determined that TPMSs meeting the requirements of this final 
rule offer an effective countermeasure in these situations. 
Accordingly, we believe that this final rule is appropriate for covered 
vehicles that are or would become subject to these provisions of FMVSS 
No. 138 because it furthers the agency's objective of preventing deaths 
and serious injuries associated with significantly under-inflated 
tires.

B. Executive Order 12866 and DOT Regulatory Policies and Procedures

    Executive Order 12866, ``Regulatory Planning and Review'' (58 FR 
51735, October 4, 1993), provides for making determinations whether a 
regulatory action is ``significant'' and therefore subject to OMB 
review and to the requirements of the Executive Order. The Order 
defines a ``significant regulatory action'' as one that is likely to 
result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or Tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or

[[Page 18182]]

    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Since the June 5, 2002 final rule, to which this final rule is 
directly related, was determined to be economically significant, the 
agency prepared and placed in the docket a Final Economic Analysis. 
This final rule likewise was determined to be economically significant. 
As a significant notice, it was reviewed under Executive Order 12866. 
The rule is also significant within the meaning of the Department of 
Transportation's Regulatory Policies and Procedures. The agency has 
estimated that compliance with this final rule will cost $823-$1,188 
million per year, since approximately 17 million vehicles are produced 
for the United States market each year. Thus, this rule would have 
greater than a $100 million effect.
    As noted above, this final rule was necessitated by the August 6, 
2003 opinion of the Court of Appeals for the Second Circuit in Public 
Citizen, Inc. v. Mineta. In that case, the court determined that the 
TREAD Act requires TPMSs to be four-tire systems, invalidated the one-
tire, 30-percent option contained in the June 5, 2002 final rule, and 
vacated the standard. As part of the final rule, NHTSA also has 
responded substantively to public comments in response to the September 
16, 2004 NPRM. Accordingly, the agency has prepared and placed in the 
docket a Final Regulatory Impact Analysis for this final rule.

C. Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of rulemaking for any proposed or final rule, it must prepare and make 
available for public comment a regulatory flexibility analysis that 
describes the effect of the rule on small entities (i.e., small 
businesses, small organizations, and small governmental jurisdictions). 
The Small Business Administration's regulations at 13 CFR Part 121 
define a small business, in part, as a business entity ``which operates 
primarily within the United States.'' (13 CFR 121.105(a)). No 
regulatory flexibility analysis is required if the head of an agency 
certifies the rule will not have a significant economic impact on a 
substantial number of small entities. SBREFA amended the Regulatory 
Flexibility Act to require Federal agencies to provide a statement of 
the factual basis for certifying that a rule will not have a 
significant economic impact on a substantial number of small entities.
    NHTSA has considered the effects of this final rule under the 
Regulatory Flexibility Act. I certify that this final rule would not 
have a significant economic impact on a substantial number of small 
entities. The rationale for this certification is that currently there 
are only four small motor vehicle manufacturers (i.e., only four with 
fewer than 1,000 employees) in the United States that will have to 
comply with this final rule. These manufacturers are expected to rely 
on suppliers to provide the TPMS hardware, and then they would 
integrate the TPMS into their vehicles.
    There are a few small manufacturers of recreational vehicles that 
will have to comply with this final rule. However, most of these 
manufacturers use van chassis supplied by the larger manufacturers 
(e.g., GM, Ford, or DaimlerChrysler) and could use the TPMSs supplied 
with the chassis. These manufacturers should not have to test the TPMS 
for compliance with this final rule since they should be able to rely 
upon the chassis manufacturer's incomplete vehicle documentation.
    Under the June 5, 2002 final rule, commenters expressed concerns 
about the impact upon aftermarket wheel and rim manufacturers, many of 
which are small businesses. These manufacturers were concerned that 
certain provisions of that final rule would have had the effect of 
restricting their ability to provide a full range of wheel and tire 
combinations to consumers, thereby negatively impacting their business. 
However, we believe that these concerns have largely been resolved by 
the final rule, which does not contain requirements for spare tires and 
aftermarket rims.
    We likewise do not believe that the final rule will have a 
significant impact upon small businesses within the automotive service 
industry, either for aftermarket sales or repair. As previously 
discussed, the agency does not consider installation of an aftermarket 
or replacement tire or rim that is not compatible with the TPMS to be a 
``make inoperative'' situation under 49 U.S.C. 30122, provided that the 
entity does not disable the TPMS malfunction indicator. As with other 
vehicle systems, we expect that vehicle manufacturers will make 
available sufficient information to permit routine maintenance and 
repair of such systems. We note also that we are permitting TPMSs to be 
reprogrammable, which we expect would further accommodate installation 
of different tires and rims. In addition, we believe that there are 
other low-cost options for maintenance and repair of TPMS sensors, such 
as strap mounting direct TPMS sensors to the vehicle's rims. For all 
these reasons, we believe that the final rule will not result in a 
significant economic impact upon aftermarket sellers of tires and rims 
or the vehicle service industry. (For further discussion related to 
these entities, see section IV.C.8 of this notice.)
    We also analyzed the impact of this proposal on 14 identified 
suppliers of TPMS systems. However, of these companies, only three have 
fewer than 750 employees. Of these three companies, one (SmarTire) has 
its headquarters located outside of the United States, and another 
(Cycloid) has only ten employees and outsources the manufacturing of 
its products.
    In conclusion, the agency believes that this final rule will not 
have a significant economic impact upon a substantial number of small 
businesses.

D. Executive Order 13132 (Federalism)

    Executive Order 13132, ``Federalism'' (64 FR 43255, August 10, 
1999), requires NHTSA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' are defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.'' Under 
Executive Order 13132, the agency may not issue a regulation with 
Federalism implications, that imposes substantial direct compliance 
costs, and that is not required by statute, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by State and local governments, the agency consults with 
State and local governments, or the agency consults with State and 
local officials early in the process of developing the proposed 
regulation. NHTSA also may not issue a regulation with Federalism 
implications and that preempts a State law unless the agency consults 
with State and local officials early in the process of developing the 
regulation.
    Although statutorily mandated, this final rule for TPMS was 
analyzed in accordance with the principles and criteria set forth in 
Executive Order 13132, and the agency determined that

[[Page 18183]]

the rule would not have sufficient Federalism implications to warrant 
consultations with State and local officials or the preparation of a 
Federalism summary impact statement. This final rule is not expected to 
have any substantial effects on the States, or on the current 
distribution of power and responsibilities among the various local 
officials.

E. Executive Order 12988 (Civil Justice Reform)

    Pursuant to Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729, February 7, 1996), the agency has considered whether this 
rulemaking would have any retroactive effect. This final rule does not 
have any retroactive effect. Under 49 U.S.C. 30103, whenever a Federal 
motor vehicle safety standard is in effect, a State may not adopt or 
maintain a safety standard applicable to the same aspect of performance 
which is not identical to the Federal standard, except to the extent 
that the State requirement imposes a higher level of performance and 
applies only to vehicles procured for the State's use. 49 U.S.C. 30161 
sets forth a procedure for judicial review of final rules establishing, 
amending, or revoking Federal motor vehicle safety standards. That 
section does not require submission of a petition for reconsideration 
or other administrative proceedings before parties may file a suit in 
court.

F. Executive Order 13045 (Protection of Children From Environmental 
Health and Safety Risks)

    Executive Order 13045, ``Protection of Children from Environmental 
Health and Safety Risks'' (62 FR 19855, April 23, 1997), applies to any 
rule that: (1) Is determined to be ``economically significant'' as 
defined under Executive Order 12866, and (2) concerns an environmental, 
health, or safety risk that the agency has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the agency must evaluate the environmental health or 
safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the agency.
    Although the TPMS final rule has been determined to be an 
economically significant regulatory action under Executive Order 12866, 
the problems associated with under-inflated tires equally impact all 
persons riding in a vehicle, regardless of age. Consequently, this 
final rule does not involve decisions based upon health and safety 
risks that disproportionately affect children, as would necessitate 
further analysis under Executive Order 13045.

G. Paperwork Reduction Act

    Under the Paperwork Reduction Act of 1995 (PRA), a person is not 
required to respond to a collection of information by a Federal agency 
unless the collection displays a valid OMB control number. As part of 
this final rule, each of the estimated 21 affected vehicle 
manufacturers is required to provide one phase-in report for each of 
two years, beginning in the fall of 2006.
    Pursuant to the June 5, 2002 TPMS final rule, the OMB has approved 
the collection of information ``Phase-In Production Reporting 
Requirements for Tire Pressure Monitoring Systems,'' assigning it 
Control No. 2127-0631 (expires 6/30/06). NHTSA has been given OMB 
clearance to collect a total of 42 hours a year (2 hours per 
respondent) for the TPMS phase-in reporting. At an appropriate point, 
NHTSA may ask OMB for an extension of this clearance for an additional 
period of time.

H. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, (15 U.S.C. 272) directs the 
agency to evaluate and use voluntary consensus standards in its 
regulatory activities unless doing so would be inconsistent with 
applicable law or is otherwise impractical. Voluntary consensus 
standards are technical standards (e.g., materials specifications, test 
methods, sampling procedures, and business practices) that are 
developed or adopted by voluntary consensus standards bodies, such as 
the Society of Automotive Engineers. The NTTAA directs us to provide 
Congress (through OMB) with explanations when we decide not to use 
available and applicable voluntary consensus standards. The NTTAA does 
not apply to symbols.
    There are no voluntary consensus standards related to TPMS 
available at this time. However, NHTSA will consider any such standards 
as they become available.

I. Unfunded Mandates Reform Act

    Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA) 
requires federal agencies to prepare a written assessment of the costs, 
benefits, and other effects of proposed or final rules that include a 
Federal mandate likely to result in the expenditure by State, local, or 
tribal governments, in the aggregate, or by the private sector, of more 
than $100 million annually (adjusted for inflation with base year of 
1995 (so currently about $112 million in 2001 dollars)). Before 
promulgating a NHTSA rule for which a written statement is needed, 
section 205 of the UMRA generally requires the agency to identify and 
consider a reasonable number of regulatory alternatives and adopt the 
least costly, most cost-effective, or least burdensome alternative that 
achieves the objectives of the rule. The provisions of section 205 do 
not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows the agency to adopt an alternative other than the 
least costly, most cost-effective, or least burdensome alternative if 
the agency publishes with the final rule an explanation of why that 
alternative was not adopted.
    This final rule is not expected to result in the expenditure by 
State, local, or tribal governments, in the aggregate, or more than 
$112 million annually, but it is expected to result in an expenditure 
of that magnitude by vehicle manufacturers and/or their suppliers. In 
the June 5, 2002 final rule, the precursor to the current final rule, 
the agency chose two compliance options (i.e., four-tire, 25-percent 
and one-tire, 30-percent) in order to minimize compliance costs with 
the standard during the phase-in period.
    However, the Second Circuit in Public Citizen, Inc. v. Mineta 
struck down the one-tire, 30-percent option. Thus, in this final rule, 
NHTSA is adopting a four-tire, 25-percent requirement, which we believe 
is consistent with safety and the mandate in the TREAD Act. We note 
that in promulgating a performance standard, NHTSA has left the door 
open for an array of technologies that may be used to meet the 
standard's requirements. With further TPMS development, we expect that 
vehicle manufacturers will have a number of technological choices that 
will provide broad flexibility to minimize their costs of compliance 
with the standard.

J. National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for the purposes of the 
National Environmental Policy Act. The agency has determined that 
implementation of this action will not have any significant impact on 
the quality of the human environment. (See section IV.C.9 of this 
notice for further discussion of the environmental impacts of this 
final rule, in response to a related public comment.)

[[Page 18184]]

K. Regulatory Identifier Number (RIN)

    The Department of Transportation assigns a regulation identifier 
number (RIN) to each regulatory action listed in the Unified Agenda of 
Federal Regulations. The Regulatory Information Service Center 
publishes the Unified Agenda in April and October of each year. You may 
use the RIN contained in the heading at the beginning of this document 
to find this action in the Unified Agenda.

L. Privacy Act

    Please note that anyone is able to search the electronic form of 
all comments received into any of our dockets by the name of the 
individual submitting the comment (or signing the comment, if submitted 
on behalf of an association, business, labor union, etc.). You may 
review DOT's complete Privacy Act Statement in the Federal Register 
published on April 11, 2000 (Volume 65, Number 70; Pages 19477-78), or 
you may visit http://dms.dot.gov.

List of Subjects in 49 CFR Parts 571 and 585

    Imports, Motor vehicle safety, Reporting and recordkeeping 
requirements, Tires.


0
In consideration of the foregoing, NHTSA is amending 49 CFR Parts 571 
and 585 as follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for Part 571 of Title 49 continues to read as 
follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.


0
2. Section 571.101 is amended by revising paragraph S5.2.3 and Table 2 
to read as follows:


Sec.  571.101  Standard No. 101; Controls and displays.

* * * * *
    S5.2.3 Except for the Low Tire Pressure Telltale, any display 
located within the passenger compartment and listed in column 1 of 
Table 2 that has a symbol designated in column 4 of that table shall be 
identified by either the symbol designated in column 4 (or symbol 
substantially similar in form to that shown in column 4) or the word or 
abbreviation shown in column 3. The Low Tire Pressure Telltale (either 
the display identifying which tire has low pressure or the display 
which does not identify which tire has low pressure) shall be 
identified by the appropriate symbol designated in column 4, or both 
the symbol in column 4 and the words in column 3. Additional words or 
symbols may be used at the manufacturer's discretion for the purpose of 
clarity. Any telltales used in conjunction with a gauge need not be 
identified. The identification required or permitted by this section 
shall be placed on or adjacent to the display that it identifies. The 
identification of any display shall, under the conditions of S6, be 
visible to the driver and appear to the driver perceptually upright.
* * * * *
BILLING CODE 4910-59-P

[[Page 18185]]

[GRAPHIC] [TIFF OMITTED] TR08AP05.000


[[Page 18186]]


[GRAPHIC] [TIFF OMITTED] TR08AP05.001


[[Page 18187]]



0
3. Section 571.138 is added to read as follows:


Sec.  571.138  Standard No. 138; Tire pressure monitoring systems.

    S1 Purpose and scope. This standard specifies performance 
requirements for tire pressure monitoring systems (TPMSs) to warn 
drivers of significant under-inflation of tires and the resulting 
safety problems.
    S2 Application. This standard applies to passenger cars, 
multipurpose passenger vehicles, trucks, and buses that have a gross 
vehicle weight rating of 4,536 kilograms (10,000 pounds) or less, 
except those vehicles with dual wheels on an axle, according to the 
phase-in schedule specified in S7 of this standard.
    S3 Definitions. The following definitions apply to this standard:
    Lightly loaded vehicle weight means unloaded vehicle weight plus 
the weight of a mass of 180 kg (396 pounds), including test driver and 
instrumentation.
    Tire pressure monitoring system means a system that detects when 
one or more of a vehicle's tires is significantly under-inflated and 
illuminates a low tire pressure warning telltale.
    Vehicle Placard and Tire inflation pressure label mean the sources 
of information for the vehicle manufacturer's recommended cold tire 
inflation pressure pursuant to Sec.  571.110 of this Part.
    S4 Requirements.
    S4.1 General. To the extent provided in S7, each vehicle must be 
equipped with a tire pressure monitoring system that meets the 
requirements specified in S4 under the test conditions specified in S5 
and the test procedures specified in S6 of this standard.
    S4.2 TPMS detection requirements. The tire pressure monitoring 
system must:
    (a) Illuminate a low tire pressure warning telltale not more than 
20 minutes after the inflation pressure in one or more of the vehicle's 
tires, up to a total of four tires, is equal to or less than either the 
pressure 25 percent below the vehicle manufacturer's recommended cold 
inflation pressure, or the pressure specified in the 3rd column of 
Table 1 of this standard for the corresponding type of tire, whichever 
is higher;
    (b) Continue to illuminate the low tire pressure warning telltale 
as long as the pressure in any of the vehicle's tires is equal to or 
less than the pressure specified in S4.2(a), and the ignition locking 
system is in the ``On'' (``Run'') position, whether or not the engine 
is running, or until manually reset in accordance with the vehicle 
manufacturer's instructions.
    S4.3 Low tire pressure warning telltale.
    S4.3.1 Each tire pressure monitoring system must include a low tire 
pressure warning telltale that:
    (a) Is mounted inside the occupant compartment in front of and in 
clear view of the driver;
    (b) Is identified by one of the symbols shown for the ``Low Tire 
Pressure Telltale'' in Table 2 of Standard No. 101 (49 CFR 571.101); 
and
    (c) Is illuminated under the conditions specified in S4.2.
    S4.3.2 In the case of a telltale that identifies which tire(s) is 
(are) under-inflated, each tire in the symbol for that telltale must 
illuminate when the tire it represents is under-inflated to the extent 
specified in S4.2.
    S4.3.3 (a) Except as provided in paragraph (b) of this section, 
each low tire pressure warning telltale must illuminate as a check of 
lamp function either when the ignition locking system is activated to 
the ``On'' (``Run'') position when the engine is not running, or when 
the ignition locking system is in a position between ``On'' (``Run'') 
and ``Start'' that is designated by the manufacturer as a check 
position.
    (b) The low tire pressure warning telltale need not illuminate when 
a starter interlock is in operation.
    S4.4 TPMS malfunction.
    (a) The vehicle shall be equipped with a tire pressure monitoring 
system that includes a telltale that provides a warning to the driver 
not more than 20 minutes after the occurrence of a malfunction that 
affects the generation or transmission of control or response signals 
in the vehicle's tire pressure monitoring system. The vehicle's TPMS 
malfunction indicator shall meet the requirements of either S4.4(b) or 
S4.4(c).
    (b) Dedicated TPMS malfunction telltale. The vehicle meets the 
requirements of S4.4(a) when equipped with a dedicated TPMS malfunction 
telltale that:
    (1) Is mounted inside the occupant compartment in front of and in 
clear view of the driver;
    (2) Is identified by the word ``TPMS'', as described under ``TPMS 
Malfunction Telltale'' in Table 2 of Standard No. 101 (49 CFR 571.101);
    (3) Continues to illuminate the TPMS malfunction telltale under the 
conditions specified in S4.4 for as long as the malfunction exists, 
whenever the ignition locking system is in the ``On'' (``Run'') 
position; and
    (4) (i) Except as provided in paragraph (ii), each dedicated TPMS 
malfunction telltale must be activated as a check of lamp function 
either when the ignition locking system is activated to the ``On'' 
(``Run'') position when the engine is not running, or when the ignition 
locking system is in a position between ``On'' (``Run'') and ``Start'' 
that is designated by the manufacturer as a check position.
    (ii) The dedicated TPMS malfunction telltale need not be activated 
when a starter interlock is in operation.
    (c) Combination low tire pressure/TPMS malfunction telltale. The 
vehicle meets the requirements of S4.4(a) when equipped with a combined 
Low Tire Pressure/TPMS malfunction telltale that:
    (1) Meets the requirements of S4.2 and S4.3; and
    (2) Flashes for a period of at least 60 seconds but no longer than 
90 seconds upon detection of any condition specified in S4.4(a) after 
the ignition locking system is activated to the ``On'' (``Run'') 
position. After this period of prescribed flashing, the telltale must 
remain continuously illuminated as long as the malfunction exists and 
the ignition locking system is in the ``On'' (``Run'') position. This 
flashing and illumination sequence must be repeated each time the 
ignition locking system is placed in the ``On'' (``Run'') position 
until the situation causing the malfunction has been corrected.
    S4.5 Written instructions.
    (a) The owner's manual in each vehicle certified as complying with 
S4 must provide an image of the Low Tire Pressure Telltale symbol (and 
an image of the TPMS Malfunction Telltale warning (``TPMS''), if a 
dedicated telltale is utilized for this function) with the following 
statement in English:

    Each tire, including the spare (if provided), should be checked 
monthly when cold and inflated to the inflation pressure recommended 
by the vehicle manufacturer on the vehicle placard or tire inflation 
pressure label. (If your vehicle has tires of a different size than 
the size indicated on the vehicle placard or tire inflation pressure 
label, you should determine the proper tire inflation pressure for 
those tires.)
    As an added safety feature, your vehicle has been equipped with 
a tire pressure monitoring system (TPMS) that illuminates a low tire 
pressure telltale when one or more of your tires is significantly 
under-inflated. Accordingly, when the low tire pressure telltale 
illuminates, you should stop and check your tires as soon as 
possible, and inflate them to the proper pressure. Driving on a 
significantly under-inflated tire causes the tire to overheat and 
can lead to tire failure. Under-inflation also reduces fuel 
efficiency and tire tread life, and may affect the vehicle's 
handling and stopping ability.
    Please note that the TPMS is not a substitute for proper tire 
maintenance, and it is the driver's responsibility to maintain

[[Page 18188]]

correct tire pressure, even if under-inflation has not reached the 
level to trigger illumination of the TPMS low tire pressure 
telltale.
    [The following paragraph is required for all vehicles certified 
to the standard starting on September 1, 2007 and for vehicles 
voluntarily equipped with a compliant TPMS MIL before that time.] 
Your vehicle has also been equipped with a TPMS malfunction 
indicator to indicate when the system is not operating properly. 
[For vehicles with a dedicated MIL telltale, add the following 
statement: The TPMS malfunction indicator is provided by a separate 
telltale, which displays the symbol ``TPMS'' when illuminated.] [For 
vehicles with a combined low tire pressure/MIL telltale, add the 
following statement: The TPMS malfunction indicator is combined with 
the low tire pressure telltale. When the system detects a 
malfunction, the telltale will flash for approximately one minute 
and then remain continuously illuminated. This sequence will 
continue upon subsequent vehicle start-ups as long as the 
malfunction exists.] When the malfunction indicator is illuminated, 
the system may not be able to detect or signal low tire pressure as 
intended. TPMS malfunctions may occur for a variety of reasons, 
including the installation of replacement or alternate tires or 
wheels on the vehicle that prevent the TPMS from functioning 
properly. Always check the TPMS malfunction telltale after replacing 
one or more tires or wheels on your vehicle to ensure that the 
replacement or alternate tires and wheels allow the TPMS to continue 
to function properly.

    (b) The owner's manual may include additional information about the 
time for the TPMS telltale(s) to extinguish once the low tire pressure 
condition or the malfunction is corrected. It may also include 
additional information about the significance of the low tire pressure 
warning telltale illuminating, a description of corrective action to be 
undertaken, whether the tire pressure monitoring system functions with 
the vehicle's spare tire (if provided), and how to use a reset button, 
if one is provided.
    (c) If a vehicle does not come with an owner's manual, the required 
information shall be provided in writing to the first purchaser of the 
vehicle.
    S5 Test conditions.
    S5.1 Ambient temperature. The ambient temperature is between 
0[deg]C (32[deg]F) and 40[deg]C (104[deg]F).
    S5.2 Road test surface. Compliance testing is conducted on any 
portion of the Southern Loop of the Treadwear Test Course defined in 
Appendix A and Figure 2 of section 575.104 of this chapter. The road 
surface is dry during testing.
    S5.3 Vehicle conditions.
    S5.3.1 Test weight. The vehicle may be tested at any weight between 
its lightly loaded vehicle weight and its gross vehicle weight rating 
(GVWR) without exceeding any of its gross axle weight ratings.
    S5.3.2 Vehicle speed. The vehicle's TPMS is calibrated and tested 
at speeds between 50 km/h (31.1 mph) and 100 km/h (62.2 mph). For 
vehicles equipped with cruise control, cruise control is not to be 
engaged during testing.
    S5.3.3 Rim position. The vehicle rims may be positioned at any 
wheel position, consistent with any related instructions or limitations 
in the vehicle owner's manual.
    S5.3.4 Stationary location. The vehicle's tires are shaded from 
direct sun when the vehicle is parked.
    S5.3.5 Brake pedal application. Driving time shall not accumulate 
during service brake application.
    S5.3.6 Range of conditions or test parameters. Whenever a range of 
conditions or test parameters is specified in this standard, the 
vehicle must meet applicable requirements when tested at any point 
within the range.
    S5.3.7 Tires. The vehicle is tested with the tires installed on the 
vehicle at the time of initial vehicle sale, excluding the spare tire 
(if provided). However, the spare tire may be utilized for TPMS 
malfunction testing purposes.
    S6 Test procedures.
    (a) Inflate the vehicle's tires to the cold tire inflation 
pressure(s) provided on the vehicle placard or the tire inflation 
pressure label.
    (b) With the vehicle stationary and the ignition locking system in 
the ``Lock'' or ``Off'' position, activate the ignition locking system 
to the ``On'' (``Run'') position or, where applicable, the appropriate 
position for the lamp check. The tire pressure monitoring system must 
perform a check of lamp function for the low tire pressure telltale as 
specified in paragraph S4.3.3 of this standard. If the vehicle is 
equipped with a separate TPMS malfunction telltale, the tire pressure 
monitoring system also must perform a check of lamp function as 
specified in paragraph S4.4(b)(4) of this standard.
    (c) If applicable, set or reset the tire pressure monitoring system 
in accordance with the instructions in the vehicle owner's manual.
    (d) System calibration/learning phase.
    (1) Drive the vehicle for up to 15 minutes of cumulative time (not 
necessarily continuously) along any portion of the test course.
    (2) Reverse direction on the course and drive the vehicle for an 
additional period of time for a total cumulative time of 20 minutes 
(including the time in S6(d)(1), and not necessarily continuously).
    (e) Stop the vehicle and deflate any combination of one to four 
tires until the deflated tire(s) is (are) at 14 kPa (2 psi) below the 
inflation pressure at which the tire pressure monitoring system is 
required to illuminate the low tire pressure warning telltale.
    (f) System detection phase.
    (1) Within 5 minutes of reducing the inflation pressure in the 
tire(s), drive the vehicle for up to 10-15 minutes of cumulative time 
(not necessarily continuously) along any portion of the test course.
    (2) Reverse direction on the course and drive the vehicle for an 
additional period of time for a total cumulative time of 20 minutes 
(including the time in S6(f)(1), and not necessarily continuously).
    (3) The sum of the total cumulative drive time under paragraphs 
S6(f)(1) and (2) shall be the lesser of 20 minutes or the time at which 
the low tire pressure telltale illuminates.
    (4) If the low tire pressure telltale did not illuminate, 
discontinue the test.
    (g) If the low tire pressure telltale illuminated during the 
procedure in paragraph S6(f), deactivate the ignition locking system to 
the ``Off'' or ``Lock'' position. After a 5-minute period, activate the 
vehicle's ignition locking system to the ``On'' (``Run'') position. The 
telltale must illuminate and remain illuminated as long as the ignition 
locking system is in the ``On'' (``Run'') position.
    (h) Keep the vehicle stationary for a period of up to one hour with 
the engine off.
    (i) Inflate all of the vehicle's tires to the same inflation 
pressure used in paragraph S6(a). If the vehicle's tire pressure 
monitoring system has a manual reset feature, reset the system in 
accordance with the instructions specified in the vehicle owner's 
manual. Determine whether the telltale has extinguished. If necessary, 
drive the vehicle until the telltale has been extinguished.
    (j) The test may be repeated, using the test procedures in 
paragraphs S6(a)-(b) and S6(d)-(i), with any one, two, three, or four 
of the tires on the vehicle under-inflated.
    (k) Simulate one or more TPMS malfunction(s) by disconnecting the 
power source to any TPMS component, disconnecting any electrical 
connection between TPMS components, or installing a tire or wheel on 
the vehicle that is incompatible with the TPMS.
    (l) TPMS malfunction detection.
    (1) Drive the vehicle for up to 15 minutes of cumulative time (not 
necessarily continuously) along any portion of the test course.

[[Page 18189]]

    (2) Reverse direction on the course and drive the vehicle for an 
additional period of time for a total cumulative time of 20 minutes 
(including the time in S6(l)(1), and not necessarily continuously).
    (3) The sum of the total cumulative drive time under paragraphs 
S6(l)(1) and (2) shall be the lesser of 20 minutes or the time at which 
the TPMS malfunction telltale illuminates.
    (4) If the TPMS malfunction indicator did not illuminate in 
accordance with paragraph S4.4, as required, discontinue the test.
    (m) If the TPMS malfunction indicator illuminated during the 
procedure in paragraph S6(l), deactivate the ignition locking system to 
the ``Off'' or ``Lock'' position. After a 5-minute period, activate the 
vehicle's ignition locking system to the ``On'' (``Run'') position. The 
TPMS malfunction indicator must again signal a malfunction and remain 
illuminated as long as the ignition locking system is in the ``On'' 
(``Run'') position.
    (n) Restore the TPMS to normal operation. If necessary, drive the 
vehicle until the telltale has extinguished.
    S7 Phase-in schedule.
    S7.1 Vehicles manufactured on or after October 5, 2005, and before 
September 1, 2006. For vehicles manufactured on or after October 5, 
2005, and before September 1, 2006, the number of vehicles complying 
with this standard (except for the provisions of S4.4 unless the 
manufacturer elects to also certify to those provisions) must not be 
less than 20 percent of:
    (a) The manufacturer's average annual production of vehicles 
manufactured on or after September 1, 2002, and before October 5, 2005; 
or
    (b) The manufacturer's production on or after October 5, 2005, and 
before September 1, 2006.
    S7.2 Vehicles manufactured on or after September 1, 2006, and 
before September 1, 2007. For vehicles manufactured on or after 
September 1, 2006, and before September 1, 2007, the number of vehicles 
complying with this standard (except for the provisions of S4.4 unless 
the manufacturer elects to also certify to those provisions) must not 
be less than 70 percent of:
    (a) The manufacturer's average annual production of vehicles 
manufactured on or after September 1, 2003, and before September 1, 
2006; or
    (b) The manufacturer's production on or after September 1, 2006, 
and before September 1, 2007.
    S7.3 Vehicles manufactured on or after September 1, 2007. Except as 
provided in S7.7, all vehicles manufactured on or after September 1, 
2007 must comply with all requirements of this standard.
    S7.4 Calculation of complying vehicles.
    (a) Carry-Forward Credits. For purposes of complying with S7.1, a 
manufacturer may count a vehicle if it is certified as complying with 
this standard and is manufactured on or after April 8, 2005, but before 
September 1, 2006.
    (b) For purposes of complying with S7.2, a manufacturer may count a 
vehicle if it:
    (1) (i) Is certified as complying with this standard and is 
manufactured on or after April 8, 2005, but before September 1, 2007; 
and
    (ii) Is not counted toward compliance with S7.1; or
    (2) Is manufactured on or after September 1, 2006, but before 
September 1, 2007.
    (c) Carry-Backward Credits. At the vehicle manufacturer's option, 
for purposes of complying with S7.1, a manufacturer may count a vehicle 
it plans to manufacture and to certify as complying with this standard 
that will be produced on or after September 1, 2006 but before 
September 1, 2007. However, a vehicle counted toward compliance with 
S7.1 may not be counted toward compliance with S7.2. If the vehicle 
manufacturer decides to exercise the option for carry-backward credits, 
the manufacturer must indicate this in its report for the production 
period corresponding to S7.1 filed pursuant to 49 CFR 585.66. The 
vehicles are counted in fulfillment of the requirements of S7.1, 
subject to actually being produced in compliance with this standard 
during the specified time period and not being counted toward the 
requirements of S7.2.
    S7.5 Vehicles produced by more than one manufacturer.
    S7.5.1 For the purpose of calculating average annual production of 
vehicles for each manufacturer and the number of vehicles manufactured 
by each manufacturer under S7.1 through S7.3, a vehicle produced by 
more than one manufacturer must be attributed to a single manufacturer 
as follows, subject to S7.5.2:
    (a) A vehicle that is imported must be attributed to the importer.
    (b) A vehicle manufactured in the United States by more than one 
manufacturer, one of which also markets the vehicle, must be attributed 
to the manufacturer that markets the vehicle.
    S7.5.2 A vehicle produced by more than one manufacturer must be 
attributed to any one of the vehicle's manufacturers specified by an 
express written contract, reported to the National Highway Traffic 
Safety Administration under 49 CFR Part 585, between the manufacturer 
so specified and the manufacturer to which the vehicle would otherwise 
be attributed under S7.5.1.
    S7.6 Small volume manufacturers. Vehicles manufactured by a 
manufacturer that produces fewer than 5,000 vehicles for sale in the 
United States during the period of September 1, 2005 to August 31, 
2006, or the period from September 1, 2006 to August 31, 2007, are not 
subject to the corresponding requirements of S7.1, S7.2, and S7.4.
    S7.7 Final-stage manufacturers and alterers. Vehicles that are 
manufactured in two or more stages or that are altered (within the 
meaning of 49 CFR 567.7) after having previously been certified in 
accordance with Part 567 of this chapter are not subject to the 
requirements of S7.1 through S7.4. Instead, vehicles that are 
manufactured in two or more stages or that are altered must comply with 
this standard beginning on September 1, 2008.

Tables to Sec.  571.138

                    Table 1.--Low Tire Pressure Warning Telltale--Minimum Activation Pressure
----------------------------------------------------------------------------------------------------------------
                                                                Column 2--maximum or        Column 3--minimum
                                                              rated inflation pressure     activation pressure
                     Column 1--tire type                     ---------------------------------------------------
                                                                 (kPa)        (psi)        (kPa)        (psi)
----------------------------------------------------------------------------------------------------------------
P-metric--Standard Load.....................................         240,          35,          140           20
                                                                  300, or       44, or          140           20
                                                                      350           51          140           20
P-metric--Extra Load........................................       280 or        41 or          160           23
                                                                      340           49          160           23

[[Page 18190]]

 
Load Range C................................................          350           51          200           29
Load Range D................................................          450           65          240           35
Load Range E................................................          550           80          240           35
----------------------------------------------------------------------------------------------------------------

PART 585--PHASE-IN REPORTING REQUIREMENTS

0
4. The authority citation for Part 585 of Title 49 continues to read as 
follows:

    Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.50.

0
5. Part 585 is amended by adding Subpart G as follows:
Subpart G--Tire Pressure Monitoring System Phase-in Reporting 
Requirements
Sec.
585.61 Scope.
585.62 Purpose.
585.63 Applicability.
585.64 Definitions.
585.65 Response to inquiries.
585.66 Reporting requirements.
585.67 Records.
585.68 Petition to extend period to file report.

Subpart G--Tire Pressure Monitoring System Phase-in Reporting 
Requirements


Sec.  585.61  Scope.

    This subpart establishes requirements for manufacturers of 
passenger cars, multipurpose passenger vehicles, trucks, and buses with 
a gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or 
less, except those vehicles with dual wheels on an axle, to submit a 
report, and maintain records related to the report, concerning the 
number of such vehicles that meet the requirements of Standard No. 138, 
Tire pressure monitoring systems (49 CFR 571.138).


Sec.  585.62  Purpose.

    The purpose of these reporting requirements is to assist the 
National Highway Traffic Safety Administration in determining whether a 
manufacturer has complied with Standard No. 138.


Sec.  585.63  Applicability.

    This subpart applies to manufacturers of passenger cars, 
multipurpose passenger vehicles, trucks, and buses with a gross vehicle 
weight rating of 4,536 kilograms (10,000 pounds) or less, except those 
vehicles with dual wheels on an axle. However, this subpart does not 
apply to manufacturers whose production consists exclusively of 
vehicles manufactured in two or more stages, and vehicles that are 
altered after previously having been certified in accordance with part 
567 of the chapter. In addition, this subpart does not apply to 
manufacturers whose production of motor vehicles for the United States 
market is less than 5,000 vehicles in a production year.


Sec.  585.64  Definitions.

    Production year means the 12-month period between September 1 of 
one year and August 31 of the following year, inclusive.


Sec.  585.65  Response to inquiries.

    At any time prior to August 31, 2007, each manufacturer must, upon 
request from the Office of Vehicle Safety Compliance, provide 
information identifying the vehicles (by make, model, and vehicle 
identification number) that have been certified as complying with 
Standard No. 138. The manufacturer's designation of a vehicle as a 
certified vehicle is irrevocable. Upon request, the manufacturer also 
must specify whether it intends to utilize either carry-forward or 
carry-backward credits, and the vehicles to which those credits relate.


Sec.  585.66  Reporting requirements.

    (a) General reporting requirements. Within 60 days after the end of 
the production years ending August 31, 2006 and August 31, 2007, each 
manufacturer must submit a report to the National Highway Traffic 
Safety Administration concerning its compliance with Standard No. 138 
(49 CFR 571.138) for its passenger cars, multipurpose passenger 
vehicles, trucks, and buses with a gross vehicle weight rating of less 
than 4,536 kilograms (10,000 pounds) produced in that year. Each report 
must--
    (1) Identify the manufacturer;
    (2) State the full name, title, and address of the official 
responsible for preparing the report;
    (3) Identify the production year being reported on;
    (4) Contain a statement regarding whether or not the manufacturer 
complied with the requirements of Standard No. 138 (49 CFR 571.138) for 
the period covered by the report and the basis for that statement;
    (5) Provide the information specified in paragraph (b) of this 
section;
    (6) Be written in the English language; and
    (7) Be submitted to: Administrator, National Highway Traffic Safety 
Administration, 400 Seventh Street, SW., Washington, DC 20590.
    (b) Report content--(1) Basis for statement of compliance. Each 
manufacturer must provide the number of passenger cars, multipurpose 
passenger vehicles, trucks, and buses with a gross vehicle weight 
rating of 4,536 kilograms (10,000 pounds) or less, except those 
vehicles with dual wheels on an axle, manufactured for sale in the 
United States for each of the three previous production years, or, at 
the manufacturer's option, for the current production year. A new 
manufacturer that has not previously manufactured these vehicles for 
sale in the United States must report the number of such vehicles 
manufactured during the current production year.
    (2) Production. Each manufacturer must report for the production 
year for which the report is filed: the number of passenger cars, 
multipurpose passenger vehicles, trucks, and buses with a gross vehicle 
weight rating of 4,536 kilograms (10,000 pounds) or less that meet 
Standard No. 138 (49 CFR 571.138).
    (3) Statement regarding compliance. Each manufacturer must provide 
a statement regarding whether or not the manufacturer complied with the 
TPMS requirements as applicable to the period covered by the report, 
and the basis for that statement. This statement must include an 
explanation concerning the use of any carry-forward and/or carry-
backward credits.
    (4) Vehicles produced by more than one manufacturer. Each 
manufacturer whose reporting of information is affected by one or more 
of the express written contracts permitted by S7.5.2 of Standard No. 
138 (49 CFR 571.138) must:
    (i) Report the existence of each contract, including the names of 
all parties to the contract, and explain how

[[Page 18191]]

the contract affects the report being submitted.
    (ii) Report the actual number of vehicles covered by each contract.


Sec.  585.67  Records.

    Each manufacturer must maintain records of the Vehicle 
Identification Number for each vehicle for which information is 
reported under Sec.  585.66(b)(2) until December 31, 2009.


Sec.  585.68  Petition to extend period to file report.

    A manufacturer may petition for extension of time to submit a 
report under this Part. A petition will be granted only if the 
petitioner shows good cause for the extension and if the extension is 
consistent with the public interest. The petition must be received not 
later than 15 days before expiration of the time stated in Sec.  
585.66(a). The filing of a petition does not automatically extend the 
time for filing a report. The petition must be submitted to: 
Administrator, National Highway Traffic Safety Administration, 400 
Seventh Street, SW., Washington, DC 20590.

    Issued: March 31, 2005.
Jeffrey W. Runge,
Administrator.
[FR Doc. 05-6741 Filed 4-7-05; 8:45 am]
BILLING CODE 4910-59-P