FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Test Notes

NORMAL OPERATION
The AIR BAG indicator is designed to light for six (±two) 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 the air bag diagnostic monitor has detected any faults in the air bag system, it will flash the air bag indicator a series of times to indicate the highest priority lamp fault code stored in memory. When the New Generation Star (NGS) Tester 007-00500 or equivalent is used to retrieve DTCs, the two digit lamp fault code is transferred to a standard DTC by the air bag diagnostic monitor.

After the lamp fault code has flashed completely five times, the AIR BAG indicator will light continuously until the ignition switch is cycled. If the AIR BAG indicator comes on when the ignition switch is turned to RUN and immediately stays on for more than eight seconds continuously, then a fault exists in the air bag indicator circuit.

The air bag diagnostic monitor incorporates a solid state circuit which shorts the air bag indicator line (Circuit 608, BK/Y) to ground to turn on the AIR BAG indicator. When the black air bag diagnostic monitor harness connector C276 is disconnected from the air bag diagnostic monitor, a shorting bar within the harness connector shorts Pin C276-11, Circuit 608 (BK/Y) and Pin C276-10, Circuit 57 (BK) together, causing a continuous lamp. This shorting bar may be removed for servicing purposes by removing the black spacer (locking wedge) in the black air bag diagnostic monitor harness connector.

The air bag diagnostic monitor requires power at Pin C277-6, Circuit 964 (DB/LG) to energize the air bag indicator circuit properly. Loss of ignition voltage at Pin C277-6, Circuit 964 (DB/LG) due to open circuit or short to ground will result in a continuous air bag indicator due to the ignition voltage applied to Pin C276-19, Circuit 640 (R/Y). An open or short to ground in the lamp circuit at Pin C276-11, Circuit 608 (BK/Y) will result in no air bag indicator (refer to Pinpoint Test C, Normal Operation).

POSSIBLE CAUSES
Continuous air bag indicator illumination can be caused by:
- a diagnostic trouble code which has flashed five times after the ignition switch was turned to RUN (after prove out) and has timed out. Recycling the ignition switch will redisplay the DTCs by flashing the lamp. The DTCs can be retrieved using New Generation Star Tester 007-00500 or equivalent.
- a disconnected or poorly connected air bag diagnostic monitor which may not push the shorting bar between Pins C276-10, Circuit 57 (BK) and C276-11, Circuit 608 (BK/Y) into its fully retracted position. This shorts the air bag indicator line to ground and causes the AIR BAG indicator to glow continuously.
- a damaged air bag diagnostic monitor.
- shorted air bag indicator wiring.
- loss of Ignition voltage at Pin C277-6, Circuit 964 (DB/LG) of the air bag diagnostic monitor.