Test Notes

Fault Code 45-Center Air Bag Sensor Not Mounted to Vehicle Properly

Normal Operation

The air bag diagnostic monitor measures the resistance between pin 21 (circuit 620, P/LB) and pin 3 (diagnostic monitor reference ground). If the air bag diagnostic monitor measures a difference of more than 2.0 ohms between pin 21 and pin 3, it will flash out code 45.

Note that circuit 620 (P/LB) is attached to the side case of the center air bag sensor and bracket. In addition, the case is grounded to the vehicle.

Also note that circuit 620 (P/LB) is spliced into another wire going to pin 22 of the air bag diagnostic monitor. Circuit 620 (P/LB) also passes through an in-line connector between the main instrument panel harness and the engine compartment harness that connects to the center air bag sensor and bracket.

Possible Causes

High resistance on pin 21 (circuit 620, P/LB) to ground can be caused by:

1. A poor connection due to loose mounting, dirt, or corrosion at the mounting location of the center air bag sensor and bracket.
2. An open or damaged wire in circuit 620 (P/LB) from pin 21 of the diagnostic monitor harness connector to center air bag sensor and bracket. This includes splices and in-line connectors.
3. An open wire or loose circuit 620 (P/LB) wire attachment inside center air bag sensor and bracket.