Test Notes

Normal Operation
The AIR BAG indicator is designed to light for six (+/-2) seconds when the ignition switch is turned to the RUN position. This initial six seconds of air bag indicator illumination is considered normal operation and is called prove out of the AIR BAG indicator. If there is an open in the air bag indicator circuit at Pin C277-11, Circuit 608 (BK/Y), a no air bag indicator fault will occur and this prove out will not be seen. If the computer in the air bag diagnostic monitor detects an open in the air bag indicator circuit and if another system fault exists, then the air bag diagnostic monitor will turn on its internal tone generator (beeper). The beep pattern is five sets of five beeps. The pattern is repeated every 30 minutes while the ignition switch is in RUN position. The five beeps do not indicate a Code 55 or any other code. The indicator circuitry must be serviced before the diagnostic trouble code can be read.

The air bag diagnostic monitor requires power at Pin C276-6, Circuit 298 (P/O) to energize the AIR BAG indicator circuit properly. Loss of ignition voltage at Pin C276-6, Circuit 298 (P/O) due to open circuit or short to ground will result in a continuous AIR BAG indicator (see Pinpoint Test D, Normal Operation, for more details) due to the ignition voltage applied to Pin C277-19, Circuit 1044 (W/Y).

If the air bag diagnostic monitor is disconnected or not firmly plugged in, a shorting bar in the black air bag diagnostic monitor harness connector C277 shorts Pins C277-10, Circuit 57 (BK) and C277-11, Circuit 608 (BK/Y) turning the lamp on continuously (see Pinpoint Test D, Normal Operation for more details).

Possible Causes
An inoperative air bag indicator circuit can be caused by a burned-out bulb or open wiring in the air bag indicator circuit.