Test Notes

Normal Operation
The air bag diagnostic monitor measures the resistance between Pin 16 (Circuit 613, BL/W) and Pin 3 (air bag diagnostic monitor reference ground). If the diagnostic monitor measures a difference of more than 2.0 ohms between Pin 16 and Pin 3, it will flash out code 21 on the air bag warning indicator.

It is important to note that Circuit 613 (BL/W) is grounded to the side of the safing sensor case and the case of the safing sensor is grounded to the vehicle in the LH cowl side trim panel retainer. A good ground connection, at both the case and the vehicle body, is important to proper circuit operation.

Possible Causes
High resistance at Pin 16 (Circuit 613, BL/W) to ground can be caused by:
1. A poor connection due to loose mounting, dirt or corrosion at the rear air bag sensor mounting surface.
2. An open or damaged wire in Circuit 613 (BL/W) from Pin 16 of the air bag diagnostic monitor connector to the safing sensor.
3. An open circuit inside the safing sensor.