Tail, Marker, and License Lamps Inoperative
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.
Tail, Marker, and License Lamps Inoperative Diagnostic Test
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior 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 tail, marker and license lamps are inoperative. Do the tail, marker and license lamps operate normally? |
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 |
|
Go to Step 8 | Go to Step 4 |
| 4 | Use the scan tool to check the body control module (BCM) park lamp switch input data. Does the scan tool indicate a park lamps ON request signal? |
Go to Step 7 | Go to Step 5 |
| 5 | Test for an open or high resistance in the park lamp switch signal circuit. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 11 | Go to Step 6 |
| 6 | Inspect for poor connections at the harness connector of the headlamp switch. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 11 | Go to Step 9 |
| 7 | Inspect for poor connections at the harness connector of the BCM. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 11 | Go to Step 10 |
| 8 | Replace the park 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 11 | - |
| 9 | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Did you complete the repair? |
Go to Step 11 | - |
| 10 |
IMPORTANT:
Perform the setup procedure for the BCM. Replace the body control module (BCM). Refer to Body Control Module Replacement
in Body Control System.Did you complete the replacement? |
Go to Step 11 | - |
| 11 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |