Test Notes

Normal Operation
The air bag diagnostic monitor measures the voltage at pins C2Ob-12 circuit 8-MA18 (WH/BU) and C2Ob-12, circuit 9-MA21 (BN/WH). The voltage at these pins is controlled by two resistors inside the air bag diagnostic monitor. Refer to Pinpoint Test F, Normal Operation. F: LFC/DTC 24 - Safing Sensor Output Feed/return Circuit Open This voltage varies with the charging system voltage as shown in the table:




Air Bag Diagnostic Monitor Typical Pin Voltages With System Connected and Engine Running

If the voltage at both of these pins exceeds 5 volts, the air bag diagnostic monitor will flash Diagnostic Trouble Code (DTC) 22.

Possible Causes
High voltage at air bag diagnostic monitor pins C2Ob-11 circuit 8-MA18 (WH/BU) and C2Ob-12, circuit 9-MA21 (BN/WH) can be caused by:
1. A short to power in the wiring harness between circuits 9-MA21 (BN/WH), 29S-MA1 (OG/BU), 8-MA22 (WH/VT), 29S-MA8 (OG), or 29S-MA11 (OG/WH) and another wire can cause high voltage on these circuits.

NOTE: The wiring harness leading to the safing sensor and bracket carries higher voltage circuits that may short to circuits 9-MA21 (BN/WH) and 29-MA1 (OG/BU).

2. A short in the air bag sliding contact between circuit 29S-MA8 (OG) and the horn or speed control wiring.
3. A short across the normally open contacts of the safing sensor.

NOTE: The voltage at circuits 29-MA15 (OG) and 7-MA2O (YE/BK) inside the safing sensor is usually battery voltage or higher. There should be an open circuit across the contacts of the safing sensor if the safing sensor is operating normally. If the sensor contacts are closed, the voltage on circuits 9-MA21 (BN/WH) and 29S-MA1 (OG/BU) would be high (at least battery voltage).

4. Vehicle charging system voltage too high. If the generator output voltage is too high (greater than 17 volts), DTC 22 may occur.