For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Fog Lights Schematics. Connector End View Reference: Master Electrical Component List.
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Verify the front fog lamps are always on. Do the front fog lamps operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3
3 | Remove the fog lamp fuse in the underhood body electrical centre (UBEC). Do the front fog lamps turn OFF? | Go to Step 4 | Repair the short to voltage in the front fog lamp supply voltage circuit. Refer to Wiring Repairs.
4 |

1. Make sure the front fog lamp switch is in the OFF position.
2. Test for a ground signal at the front fog lamp relay control circuit terminal in the UBEC. Refer to Circuit Testing.

Was a ground signal found?

Go to Step 5

Replace the UBEC. Refer to Underhood Electrical Center or Junction Block Replacement.

5 | Test the front fog lamp relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | System OK | Go to Step 6
6 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | System OK | Replace the BCM. Refer to Control Module References, for replacement, setup, and programming.