Test Notes

Normal Operation
Circuit 9-MA19 (BN/GN) is riveted to the side of the safing sensor and bracket housing and the housing is grounded to the vehicle. A resistor inside the air bag diagnostic monitor is connected to pin C2Oa-16, circuit 9-MA19 (BN/GN) and a 5 volt reference voltage. If circuit 9-MA19 (BN/GN) is properly grounded, the voltage at pin C2Oa-16, circuit 9-MA19 (BN/GN) will be 0 volts. If the voltage on circuit 9-MA19 (BN/GN) is greater than 0.7 volts, the air bag diagnostic monitor will flash Diagnostic Trouble Code (DTC) 21, indicating that the safing sensor and bracket is not grounded properly to the vehicle.

Possible Causes
High voltage at air bag diagnostic monitor pin C2Oa-16, circuit 9-MA19 (BN/GN), can be caused by:
1. A poor connection due to loose mounting, dirt, or corrosion at the safing sensor and bracket mounting surface.
2. An open or damaged wire in circuit 9-MA19 (BN/GN).
3. An open wire or loose rivet inside the safing sensor.