B: The Air Bag Warning Indicator Is Illuminated Continuously
Electrical Schematic:
Normal Operation
The air bag indicator is designed to illuminate for six (± two) seconds when the ignition key is turned to the ON position. This initial six seconds of air bag indicator illumination (continuous warning indicator) is considered normal operation and is called "prove out" of the air bag indicator. If the air bag diagnostic monitor detects any faults in the air bag system following prove out, it will flash the air bag indicator a series of times to indicate the fault code that has been detected. If the air bag indicator comes on when the ignition key is turned to the ON position and 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 that shorts the air bag indicator line (circuit 952 "R/GN") to ground to turn the air bag indicator on. When the gray air bag diagnostic monitor connector is unplugged from the air bag diagnostic monitor, a shorting bar within the harness connector connects pins 4 (air bag indicator) and 5 (ground) together. Therefore, the shorting bar will turn the air bag indicator on whenever the gray air bag diagnostic monitor harness connector is disconnected. Because the shorting bar makes a continuous connection between pins 4 and 5 when the connector is disconnected, the air bag indicator will not flash. Instead the warning indicator will be illuminated continuously.
If the computer within the air bag diagnostic monitor fails to "boot up" with the key ON, the warning indicator driver circuit will automatically turn the air bag indicator ON continuously, indicating a problem 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 the following:
1. A disconnected or poorly connected air bag diagnostic monitor may not push the shorting bar between pins 4 and 5 into its fully retracted position. This shorts the air bag indicator line to ground and causes the air bag indicator to illuminate continuously.
2. Shorted air bag indicator wiring.
3. A faulty air bag diagnostic monitor.
Pinpoint Test Steps:
B1:
