45: Center Primary Crash Sensor Not Mounted Properly

Electrical Schematic:

Normal Operation
The air bag diagnostic monitor measures the resistance between pin 21 (Circuit 620, P/LB) and pin 3 (diagnostic monitor reference ground). It 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 casing of the radiator support center air bag primary crash sensor and bracket. In addition, the case is grounded to the vehicle.

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 primary crash sensor and bracket.
2. An open or damaged wire in Circuit 620 (P/LB) from pin 21 of the diagnostic monitor harness connector to radiator support center air bag primary crash sensor and bracket. This includes splices and in-line connectors.
3. An open wire or loose (Circuit 620 P/LB) wire attachment inside radiator support center air bag primary crash sensor and bracket.

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

Check splice and in-line connectors for poor crimps, etc.

Pinpoint Test Steps:

45-1 - 45-4: