Fault Code 45 Front Left Impact Sensor Incorrectly Mounted

FAULT CODE 45
Front Left Impact Sensor Incorrectly Mounted to vehicle


Normal Operation
The Air Bag Diagnostic Module (DM) monitors the resistance value between pins 21 and 3. If a resistance of greater than 2.0 Ohm is detected the MIL Lamp will illuminate and fault code 45 will be present, indicating incorrect mounting of the LH impact sensor. Secure connections to ground at both the sensor case and the vehicle are necessary to avoid this fault.

Possible Causes
- Poor or dirty connection between LH impact sensor case and vehicle ground.
- Poor or dirty termination at impact sensor internal ground.
- Open circuit on wiring between DM pin 21 and impact sensor ground terminal.

Fault Diagnosis
1. Circuit - check
- Disarm the Airbag/SRS system, and disconnect the battery earth lead.
- Disconnect the DM.
- Measure resistance between DM pin 21 and pin 3 (ground).
- Is the resistance greater than 2.0 Ohm.

Yes - Proceed to step 2.
No - Renew DM.

2. Sensor - check
- Disconnect RH impact sensor from main harness.
- Measure resistance between sensor terminal 4 and ground.
- Is the resistance greater than 2.0 Ohm.

Yes -
- Remove sensor from mountings, clean all mounting surfaces (including chassis) and refit.
- Re-test resistance and renew sensor if value is still above 2.0 Ohm.

No -
- Examine harness for broken, dirty or incorrectly seated connectors.

3. On completion.
- Arm and verify Airbag/SRS system.

Electrical Schematic-Front Left Impact Sensor incorrectly Mounted To Vehicle, Fig.1:

1. Instrument Panel Fuse
2. Engine Compartment Fuse
3. Safing Sensor
4. Cable Reel Cassettes
5. Driver-side airbag
6. Passenger-side airbag
7. RH Impact Sensor
8. LH Impact Sensor
9. Airbag MIL Lamp
10. Diagnostic Module