[Federal Register Volume 62, Number 179 (Tuesday, September 16, 1997)]
[Pages 48708-48709]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24568]



National Highway Traffic Safety Administration
[Docket No. 97-058; Notice 1]

General Motors; Receipt of Application for Decision of 
Inconsequential Noncompliance

    General Motors Corporation (GM) of Warren, Michigan, has determined 
that some of its 1997 model Chevrolet Corvettes fail to meet the 
requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 124, 
``Accelerator Control Systems,'' and has filed an appropriate report 
pursuant to 49 CFR Part 573, ``Defects and Noncompliance Reports.'' GM 
has 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 
    This notice of receipt of an application is published under 49 
U.S.C. 30118 and 30120 and does not represent any agency decision or 
other exercise of judgment concerning the merits of the application.
    In FMVSS No. 124, Paragraph S5.2 requires the throttle to return to 
idle position within the time limits specified in S5.3, whenever any 
component of the accelerator control system is disconnected or severed 
at a single point. S5.3 requires return to idle within 3 seconds for 
any vehicle exposed to temperatures of 0 degrees to -40 degrees F (-18 
degrees to -40 degrees C).
    During the 1997 model year, GM produced 9,500 Chevrolet Corvettes 
which may not comply with FMVSS No. 124. The vehicles' accelerator 
pedal module assembly may not return to idle condition within the 
required time.
    GM supports its application for inconsequential noncompliance with 
the following:
    The Chevrolet Corvette employs an electronic throttle control which 
adjusts the throttle position based on input from the accelerator pedal 
position. The accelerator pedal is equipped with three springs, any two 
of which are capable of returning the pedal to rest position. Once this 
occurs, the throttle returns to idle position approximately 0.2 seconds 
later. A test run in early May, however, raised a question about the 
ability of the pedal assembly to return at low temperatures.
    GM believes that the failure of the pedal assembly to meet the 
throttle closing time requirements of FMVSS No. 124 at extremely low 

[[Page 48709]]

is inconsequential to motor vehicle safety for the following reasons.
    1. Vehicle Controllability--In the unlikely event that all of the 
prerequisites necessary for the noncompliance occurred--that is, a 
return spring was disconnected or severed on a pedal assembly with 
residual oil, and the vehicle soaked at ambient temperatures below 32 
degrees C--the vehicle would continue to be controllable both by the 
service brakes and as a result of the Brake Torque Management System.
    2. Reliability of the Accelerator Springs--The condition which is 
the subject of GM's noncompliance decision can only occur if one of the 
return springs is severed or disconnected. The springs in the Corvette 
pedal assembly, however, have extremely high reliability and are not 
likely to fail in the real world.
    3. Condition Requires Extreme Temperatures; Pedal Assembly Warms 
Quickly--As mentioned above, the root cause of the noncompliance 
condition is the residual oil on the pedal assemblies congealing below 
-32 degrees C. Testing at temperatures above that level resulted in 
full compliance with the FMVSS No. 124 time limits for all pedal 
assemblies tested. Therefore, the ambient temperatures required for the 
possibility of this noncompliance to exist are severe. Even if a 
vehicle with a disconnected return spring soaked under the necessary 
harsh conditions for a sufficient time to congeal the residual oil, the 
potential for the noncompliance to occur would exist for only a short 
time, because the pedal assembly would warm up quickly with activation 
of the vehicle heating system.
    4. Condition is Self-correcting--Durability testing indicates that 
the condition improves with wear. Bench testing was conducted on five 
production pedal assemblies with poor return times. The pedals on these 
assemblies were cycled at room temperature. Since the vast majority of 
driving is done with a only limited pedal movement, each cycle 
consisted of a 10% application of pedal travel. Every 2,000 cycles the 
pedal return at (-40 degrees C) was checked. The results, shown in 
Figure 5 [of the application], indicate that most pedals will return 
within the specified time limit after 10,000 cycles, and all pedals 
will easily meet the time limits after 15,000 cycles.
    5. Warranty Data--GM has reviewed recent warranty data for the 1997 
Corvette, as well as complaint data. We are unaware of any data 
suggesting the subject condition is a real world safety issue.
    Interested persons are invited to submit written data, views, and 
arguments on the application of GM described above. Comments should 
refer to the docket number and be submitted to: Docket Section, 
National Highway Traffic Safety Administration, Room 5109, 400 Seventh 
Street, SW, Washington, DC 20590. It is requested but not required that 
six copies be submitted.
    All comments received before the close of business on the closing 
date indicated below will be considered. The application and supporting 
materials, and all comments received after the closing date, will also 
be filed and will be considered to the extent possible. When the 
application is granted or denied, the notice will be published in the 
Federal Register pursuant to the authority indicated below.

    Comment closing date: October 16, 1997.

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

    Issued on: September 9, 1997.
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.
[FR Doc. 97-24568 Filed 9-15-97; 8:45 am]