Inspection and Verification

INSPECTION AND VERIFICATION

1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.

VISUAL INSPECTION CHART

Electrical
- Battery junction box (BJB) fuse 31 (15A) (fog lamps)
- Bulb(s)
- Wiring, terminals or connectors
- Fog lamp relay
- Headlamp switch
- Smart junction box (SJB)

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

NOTE:
- Make sure the headlamp switch is in the OFF position.
- Make sure the multifunction switch is in the LOW BEAM position.

4. NOTE: Make sure to use the latest scan tool release software.

If the cause is not visually evident, connect the scan tool to the data link connector (DLC).

5. NOTE: The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.

If the scan tool does not communicate with the VCM:
- Check the VCM connection to the vehicle.
- Check the scan tool connection to the VCM.
- Refer to Information Bus (Module Communications Network), No Power To The Scan Tool, to diagnose no communication with the scan tool.

6. If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.
- Verify the scan tool operation with a known good vehicle.
- Refer to Information Bus (Module Communications Network) to diagnose no response from the PCM.

7. Carry out the network test.
- If the scan tool responds with no communication with the SJB, refer to Information Bus (Module Communications Network).
- If the network test passes, retrieve and record the continuous memory DTCs.

8. Clear the continuous DTCs and carry out the self-test diagnostics for the SJB.
9. If the DTCs retrieved are related to the concern, go to DTC Charts. For all other DTCs, refer to Body Control Systems (Multifunction Electronic Control Module). Diagnostic Trouble Code Tests and Associated Procedures
10. If no DTCs related to the concern are retrieved, GO to Symptom Chart. Symptom Related Diagnostic Procedures