With both the ignition switch in the RUN position and the park lamps or low beam head lamps ON, the fog lights will illuminate when the driver presses the fog lamp switch. When the fog lamps are on the BCM will turn the fog lamp indicator on by supplying battery voltage to the indicator LED through the indicator control circuit. The indicator is grounded through the headlamp switch low reference circuit to the BCM.

Schematic Reference

Fog Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for Scan Tool Information

Ignition ON, command the front fog lamps ON and OFF with a scan tool. The front fog lamp indicator should turn on and off.

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Ignition ON, headlamps ON, connect a test lamp between the indicator control circuit terminal 8 and ground. The test lamp should not be illuminated.

⇒	If the test lamp is illuminated, test the indicator control circuit for a short to voltage. If the circuit tests normal replace the BCM.

3. Command the front fog lamps ON with a scan tool. The test lamp should be illuminated.

⇒	If the test lamp is not illuminated, test the indicator control circuit for an open/high resistance or short to ground. If the circuit tests normal replace the BCM.

4. If all the circuits test normal replace the headlamp switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.