Fog Lamps Inoperative - Rear
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Fog Lamps Inoperative - Rear Diagnostic Test
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Fog Lights Schematics Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System |
|||
| 1 | Did you perform the Lighting Systems Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 | Verify that the rear fog lamp is inoperative. Does the rear fog lamp operate normally? |
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Test the inoperative bulb or tail lamp printed circuit board for an open or poor terminal contact and replace as necessary. Refer to Circuit Testing
in Wiring Systems or Tail Lamp Bulb Replacement or Tail Lamp Circuit Board Replacement . Did you find and correct a condition? |
Go to Step 15 | Go to Step 4 |
| 4 | With the engine Off, turn the key to RUN and the headlamp switch to PARK. Do the park lamps illuminate? |
Go to Step 5 | Go to Symptoms - Lighting Systems |
| 5 | Inspect the RR FOG fuse. Is the fuse open? |
Go to Step 6 | Go to Step 7 |
| 6 | Test for a short to ground in the rear fog lamp supply voltage circuit. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct a condition? |
Go to Step 15 | Go to Step 13 |
| 7 |
|
Go to Step 10 | Go to Step 8 |
| 8 | Test the rear fog lamp switch signal and ground circuits for an open or high resistance. Refer to Circuit Testing
andWiring Repairs
in Wiring Systems. Did you find and correct a condition? |
Go to Step 15 | Go to Step 9 |
| 9 |
|
Go to Step 14 | Go to Step 11 |
| 10 | Test for an open or high resistance in the rear fog lamp supply voltage circuit and the ground circuit. Refer to Circuit Testing
andWiring Repairs
in Wiring Systems. Did you find and correct a condition? |
Go to Step 15 | Go to Step 13 |
| 11 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 15 | Go to Step 12 |
| 12 |
IMPORTANT:
Perform the setup procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement
in Body Control System.Did you complete the replacement? |
Go to Step 15 | - |
| 13 | Replace the rear fog lamp relay. Refer to Relay Replacement (Within an Electrical Center)
or Relay Replacement (Attached to Wire Harness)
in Wiring Systems. Did you complete the repair? |
Go to Step 15 | - |
| 14 | Replace the rear fog lamp switch. Refer to Headlamp Switch Replacement . Did you complete the repair? |
Go to Step 15 | - |
| 15 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |