[Federal Register Volume 61, Number 19 (Monday, January 29, 1996)]
[Notices]
[Pages 2865-2866]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-1505]



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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
[Docket No. 95-57; Notice 2]


General Motors Corp.; Grant of Application for Decision of 
Inconsequential Noncompliance

    General Motors Corporation (GM) of Warren, Michigan, determined 
that some of its vehicles failed to comply with the requirements of 49 
CFR 571.108, Federal Motor Vehicle Safety Standard (FMVSS) No. 108, 
``Lamps, Reflective Devices, and Associated Equipment,'' and filed an 
appropriate report pursuant to 49 CFR part 573, ``Defect and 
Noncompliance Reports.'' GM also applied to be exempted from the 
notification and remedy requirements of 49 U.S.C. Chapter 301--``Motor 
Vehicle Safety'' on the basis that the noncompliance is 
inconsequential to motor vehicle safety.
    Notice of receipt of the application was published on July 26, 
1995, and an opportunity afforded for comment (60 FR 38392).
    Paragraph S5.5.10(d) of FMVSS No. 108 requires that ``all other 
lamps [not mentioned in Paragraphs S5.5.10(a-c) which includes all stop 
lamps such as center high-mounted stop lamps (CHMSLs)] shall be wired 
to be steady-burning.''
    During the 1995 model year, GM manufactured a total of 96,607 GMC 
and Chevrolet Suburban, GMC Yukon, and Chevrolet Tahoe vehicles with 
CHMSLs that were inadvertently wired in a manner which permits the 
CHMSLs to momentarily flash under certain conditions while the driver 
is in the process of activating or deactivating the hazard flashers. As 
a result, they do not meet the requirement of Paragraph S5.5.10(d) that 
they be ``wired to be steady-burning.'' While GM designed the vehicles 
to meet this requirement, it subsequently discovered a transient 
contact condition inside the multi-function (stop lamp, CHMSL, turn 
signal, and hazard flasher) switch which occasionally causes the CHMSL 
to flash while the driver is in the process of turning the hazard 
flasher switch ``on'' or ``off.'' The error was corrected in production 
in March 1995 by adding a brake lamp relay to the I/P harness to 
provide isolation from the multi-function switch transient.
    GM supported its application for inconsequential noncompliance with 
the following:

    The CHMSL performs properly at all times when the service brakes 
are applied. The transient condition will not occur if the service 
brakes are applied when the driver activates or deactivates the 
hazard flasher switch. Therefore, the CHMSL will not flash when it 
is required to be steady-burning. The CHMSL will not flash if the 
ignition switch is in the ``off'' position. Thus, the condition will 
not occur if the hazard flashers are turned ``off'' or ``on'' when 
the ignition is off and the vehicle is parked at the side of the 
road, for example.
    If the CHMSL flashes at all, it will illuminate a maximum of 
three times during the transient condition, with each pulse lasting 
0.5 [millisecond (ms)] to 4.0 ms. The entire unintended event, in 
its worst case, lasts no more than 125.8 ms. This extremely short 
duration is likely to go entirely unnoticed by following drivers in 
many instances. In the event that it is noticed, it is not likely to 
be confused with anything other than the hazard flashers. Since the 
flashers will be activated while the unintended condition occurs, 
but the brake lamps will not be, this will not present a safety 
risk.
    The CHMSL otherwise meets all of the requirements of FMVSS 108.
    In a 1989 interpretation, NHTSA discussed the difference between 
the requirements that stop lamps be steady-burning and hazard 
warning lights flash. NHTSA explained:
    Standard No. 108 requires stop lamps to be steady-burning, and 
hazard warning signal lamps to flash (generally through the turn 
signal lamps). The primary reason for the distinction is that the 
stop lamps are intended to be operated while the vehicle is in 
motion, while hazard warning lamps are intended to indicate that the 
vehicle is stopped. Each lamp is intended to convey a single, easily 
recognizable signal. If a lamp which is ordinarily steady burning 
begins to flash, the agency is concerned that the signal will prove 
confusing to motorists, thereby diluting the effectiveness.

August 8, 1989 letter from S.P. Wood, Acting Chief Counsel, NHTSA, 
to L.P. Egley

    While this condition technically causes a lamp which is 
ordinarily steady burning to begin to flash, it will not likely 
``prove confusing to motorists, thereby diluting its 
effectiveness,'' because it will not occur if the service brakes are 
applied. Even if the condition were mistaken for a brake signal 
(which is doubtful since CHMSLs do not flash with brake lamp 
activation), the following driver would not likely react to it. 
According to recent research studies conducted by GM, as well as 
field data, it takes a following driver at least 0.5 seconds to 
react to a signal and apply the service brakes once [a] preceding 
vehicle's brake lamps are activated. Given the extremely short 
duration of the transient CHMSL condition, the misinterpreted signal 
would be gone long before the following driver could respond.
    Hazard flashers are not frequently used. Thus, the exposure of 
following drivers to the noncompliant condition would be very 
limited. This is particularly true because of the transient nature 
of the condition, its short duration, and the fact that it will not 
occur at all if the service brakes are applied or the vehicle's 
ignition is off.
    GM is not aware of any accidents, injuries, owner complaints, or 
field reports related to this condition.

    No comments were received on the application.
    GM states that ``[t]he entire unintended event, in its worst case, 
lasts no more than 125.8 ms.'' This is \1/8\th of a second. As GM 
further stated, according its research studies and field data, it takes 
a following driver at least half a second to react to a signal and to 
apply the service brakes once a preceding vehicle's brakes are 
activated. NHTSA finds this a convincing argument that the transient 
activation of the CHMSL, a false signal, is highly unlikely to mislead 
a following driver 

[[Page 2866]]
into applying the service brakes when there is no need to do so.
    In consideration of the foregoing, it is hereby found that the 
applicant has met its burden of persuasion that the noncompliance 
herein described is inconsequential to safety. Accordingly, the 
applicant is hereby exempted from its obligations to provide notice of 
the noncompliance as required by 49 U.S.C. 30118, and to remedy the 
noncompliance as required by 49 U.S.C. 30120.

49 U.S.C. 30118, 30120; delegations of authority at 49 CFR 1.50 and 
501.8).

    Issued on: January 23, 1996.
Barry Felrice,
Associate Administrator for Safety Performance Standards.
[FR Doc. 96-1505 Filed 1-26-96; 8:45 am]
BILLING CODE 4910-59-P