Test Notes

Normal Operation
The AIR BAG warning indicator is designed to illuminate for six (+/- two) seconds when the ignition switch is turned to RUN. This initial six seconds of air bag warning indicator illumination (continuous lamp) is considered normal operation and is called prove out of the AIR BAG warning indicator. If the air bag diagnostic monitor detects any faults in the air bag system following prove out, it will flash the AIR BAG warning indicator a series of times to indicate the diagnostic trouble code that has been detected. If the AIR BAG warning indicator comes on when the ignition switch is turned to RUN and stays on for more than eight seconds continuously, then a fault exists in the air bag warning indicator circuit.

The air bag diagnostic monitor incorporates a solid-state circuit that shorts the AIR BAG warning indicator line (Circuit 608, BK/Y) to ground to turn the air bag warning indicator on. When the gray air bag diagnostic monitor harness connector is unplugged from the air bag diagnostic monitor, a shorting bar within the harness connector connects Pins C2000-4 (AIR BAG warning indicator) and C2000-5 (ground) together. The shorting bar will turn the AIR BAG warning indicator on whenever the gray air bag diagnostic monitor harness connector is disconnected. Because the shorting bar makes a continuous connection between Pins C2000-4 and C2000-5 when the connector is disconnected, the AIR BAG warning indicator will not flash-instead, it will glow continuously.

When the ignition switch is turned to RUN, the air bag diagnostic monitor wakes up and, after approximately six seconds, turns the AIR BAG warning indicator OFF. If the air bag diagnostic monitor fails to wake up, the lamp driver circuit will automatically turn the AIR BAG warning indicator ON continuously, indicating a concern in the air bag diagnostic monitor or at the gray air bag diagnostic monitor connector.

Possible Causes
Continuous illumination of the AIR BAG indicator can be caused by:
- A disconnected or poorly connected air bag diagnostic monitor which may not push the shorting bar between Pins C2000-4 and C2000-5 into its fully-retracted position. This shorts the air bag warning indicator line to ground and causes the AIR BAG warning indicator to glow continuously.
- Shorted air bag warning indicator wiring.
- A damaged air bag diagnostic monitor.