Dear [ ]:
This responds to your letter requesting an interpretation of the advanced air bag requirements of Federal Motor Vehicle Safety Standard No. 208, Occupant crash protection (FMVSS No. 208). You specifically ask whether the telltale requirements of S19.2.2 would prohibit a design that would cause the telltale to flash for five seconds to inform vehicle occupants that the status of the air bag has changed. You have also requested that the name of your company be kept confidential due to the confidential business nature of the contemplated design. That request is granted. I am pleased to provide a response to your request for interpretation. The design discussed in your letter would not be prohibited by S19.2.2.
On May 12, 2000, the National Highway Traffic Safety Administration (NHTSA) published a final rule in the Federal Register (65 FR 30680) requiring advanced air bags in all passenger cars, multi-purpose vehicles, light trucks and buses with a gross vehicle weight rating (GVWR) of 8,500 lb or less. The phase-in for these new requirements begins September 1, 2003. That final rule established new, advanced air bag performance requirements to minimize the risk of injury to children, as well as new requirements to enhance protection of small and mid-size adults.
Under S19.2.2, any air bag system that uses automatic suppression technology to satisfy the requirements of the standard must have a telltale that illuminates whenever the air bag is suppressed and that does not illuminate whenever the air bag is active, except that the telltale need not illuminate when the passenger seat is unoccupied. S19.2.2 is silent as to how the telltale must operate while the status of the air bag is in transition. Nor does the provision address flashing, as opposed to continuous, illumination. S20.2 tests the air bag suppression system by placing a child restraint, test dummy, or human in the passenger seat, starting the engine and then waiting 10 seconds before determining the status of the air bag.
Under the design contemplated by your company, the required telltale would flash for five seconds to notify the vehicle occupants that the status of the air bag has changed. You state that you believe this feature will better alert both drivers and front seat passengers when the status of the air bag has changed than simply turning the telltale on or off. Under your design, the five seconds of flashing would be triggered by a change in status from "active" to "inactive" and vice versa. After the five-second flashing period has ended, the telltale would either illuminate steadily or go out, depending on the activation status of the air bag.
Nothing in S19.2.2 prohibits a telltale that flashes to inform vehicle occupants that the air bag has transitioned from an active to inactive status. While S19.2.2(h) prohibits telltale illumination other than when the air bag has been turned off (except during a bulb check), the intention behind S19.2.2(h) is to let vehicle occupants know whether or not their air bag is suppressed without requiring them to discern varying light intensities or other potentially confusing designs. Accordingly, we interpret the standard to permit a system that transitions from continually burning to flashing for a brief period of time, no more than 10 seconds, after the air bag has been reactivated.
Thus, your contemplated design would be permissible under S19.2.2 as long as the telltale only flashes when the air bag is actually suppressed or for a brief period of time after the air bag has been reactivated. Please note that while nothing in the standard would prohibit the telltale from continuously flashing whenever the air bag is suppressed, such designs could be unduly annoying and could lead a vehicle owner to disconnect the telltale. Likewise, an occupant detection system that regularly turned the air bag on and off because the status of the air bag was constantly in transition would be problematic.
Finally, we note that while a flashing design is not prohibited, any vehicle manufacturer choosing to incorporate such a design in its telltale would need to either provide an alternative means of determining whether the air bag is active or suppressed consistent with S19.2.3 or limit the flash to less than 10 seconds. This is because the test procedure set forth in S20.2, and its corollaries in S22.2 and S26.2, require the manufacturer to provide a mechanism that NHTSA can use to determine whether the automatic suppression system is, in fact, able to reliably classify the front passenger seat occupant. For a continually flashing system, the alternative means is necessary to differentiate between a properly functioning system and a problematic system that is continually transitioning between suppression and activation.
I hope this letter addresses your concerns. Please feel free to contact Rebecca MacPherson of my staff at (202) 366-2992 should you have any additional questions.