General Motors North America, Notice of Application for Decision of Inconsequential Noncompliance

General Motors North America (GM) has determined that on some 1995-1999 model year GMC and Chevrolet trucks and on some 1997-1999 Pontiac Grand Prix cars, the center high-mounted stop lamp (CHMSL) could briefly illuminate if the hazard flasher switch is depressed to its limit of travel. This condition would not meet the lighting requirements of S5.5.4 of Federal Motor Vehicle Safety Standard (FMVSS) No. 108, “Lamps, reflective devices, and associated equipment.” Pursuant to 49 U.S.C. 30118(d) and 30120 (h), GM has petitioned for a determination that this condition is inconsequential to motor vehicle safety and has filed an appropriate report pursuant to 49 CFR part 573, “Defect and Noncompliance Reports.”

We are publishing this notice of receipt of an application as required by 49 U.S.C. 30118 and 30120. This action does not represent any agency decision of other exercise of judgment concerning the merits of the application.

FMVSS No. 108 establishes the requirements for signaling to enable safe operation in darkness and other conditions of reduced visibility. Under S5.5.4 of FMVSS No. 108, the CHMSL on each vehicle shall be activated only upon application of the service brakes. During Model Year 1995-1999 GM produced 3,375,393 vehicles with a CHMSL that could briefly illuminate if the hazard flasher switch is depressed to its limit of travel. The vehicles that may have this condition are 1995-1999 model year GMC and Chevrolet trucks and some 1997-1999 Pontiac Grand Prix cars.

GM supports its application for inconsequential noncompliance by stating the following:

The possibility of unintended CHMSL illumination is very low, for several reasons. Hazard flashers are infrequently used in service. The condition can occur only when the hazard flasher switch is at the extreme bottom of travel. To turn the hazard flashers on or off, one need merely push the hazard flasher switch. It is not necessary to push the switch all the way to its limit of travel. Even when the switch is depressed all the way to its limit of travel, CHMSL illumination may not occur. In approximately 50% of the switches it would be moderately difficult to get a CHMSL activation. With these switches, it is also necessary to apply a side force to the hazard flasher switch (in addition to having the switch at its bottom of travel) before the CHMSL might illuminate.

Even if the condition does occur, the duration of unintended CHMSL illumination would be very brief. The hazard flasher switch requires less than a second in total to turn the flashers on or off, and only for a fraction of this total time would the switch be all the way to its limit of travel.

About one-third of the affected vehicles have incandescent CHMSLs. In these vehicles, visible illumination of the CHMSL would not occur unless the hazard switch were depressed to its full limit of travel and held there long enough for the incandescent bulb filaments to heat and become visible. Therefore, unless the hazard switch was deliberately held at its limit of travel, and possibly with a side force, any unintended CHMSL illumination would be momentary and as a practical matter virtually imperceptible.

Even if a visible CHMSL illumination occurs upon hazard flasher activation, it would almost certainly have no adverse effect on safety. Hazard flasher lights are typically used when the vehicle is off the road or out of traffic. However, if a CHMSL illuminated due to this condition when the vehicle was on the road, a following driver would likely see a brief single flash of the CHMSL. As a practical matter, the following driver might not notice this flash at all. Even if he or she did, there would seem to be no likelihood of driver confusion or inappropriate responses. In reaching this view, we have considered the following situations and would invite the agency's consideration of them as well:

A driver who turns on the hazard flasher switch does so in order to alert others to some situation that the driver judges to be a highway safety hazard. Indeed, the owner's manual in each of these vehicles states as much: Your hazard warning flashers let you warn others. They also let police know you have a problem.

When the driver turns them on, the hazard lamps on these vehicles commence flashing immediately after the driver releases the switch. In this situation, any momentarily illuminated CHMSL would augment the hazard alert to following drivers.

If the hazard flasher switch is being turned off, the CHMSL could be illuminated momentarily while the hazard lamps are flashing. A following driver is unlikely to react inappropriately to a momentary CHMSL illumination when two hazard lamps are already flashing.

In many situations, it seems likely that a driver suddenly approaching a hazard situation might want to slow down, and therefore the service brakes would be applied when the hazard switch is depressed. In this case, the CHMSL would remain illuminated by the service brakes as required by FMVSS 108. This situation would pose no safety or compliance issue because the CHMSL would already be on.

The CHMSL (and the remainder of the vehicle lighting) otherwise meets all of the requirements of FMVSS 108.

GM is not aware of any accidents, injuries, owner complaints or field reports for the subject vehicles related to this condition.

NHTSA has previously granted inconsequential treatment for a similar condition. In 1995, General Motors petitioned for inconsequential treatment for a noncompliance while the hazard switch was being used (reference Mr. Milford Bennett letter to Dr. Ricardo Martinez dated June 16, 1995). The agency subsequently granted inconsequential treatment for this condition (reference Docket 95-57, Notice 2 published in the Federal Register, 61 FR 2865, January 29, 1996). No one opposed the application. NHTSA found in that situation that “the transient activation of the CHMSL, a false signal, is highly unlikely to mislead a following driver,” at 2865-2866.

The current situation would appear to be even less of a highway safety issue, because (a) the previous condition could occur at various positions within the normal operating travel of the hazard switch, while the current condition can only occur at the extreme bottom of travel of the hazard switch; and (b), the previous condition could involve up to three momentary flashes of the CHMSL, while the current condition only has the potential for a single momentary illumination of the CHMSL.

Interested persons are invited to submit written data, views, and arguments on the application described above. Comments should refer to the docket number and be submitted to : U.S. Department of Transportation, Docket Management, Room PL-401, 400 Seventh Street, SW, Washington, DC, 20590. It is requested that two 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: June 15, 2000.

(49 U.S.C. 301118, 301120; delegations of authority at 49 CFR 1.50 and 501.8)