Headlamps Inoperative - Flash to Pass
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.
Headlamps Inoperative - Flash to Pass Diagnostic Test
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) 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 flash to pass (FTP) is inoperative. Does the FTP operate normally? |
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 | Do the high beam headlamps operate normally? | Go to Symptoms - Lighting Systems | Go to Step 4 |
| 4 |
|
Go to Step 6 | Go to Step 5 |
| 5 | Test the headlamp switch flash to pass signal circuit for an open or high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct a condition? |
Go to Step 10 | Go to Step 7 |
| 6 | Inspect for poor connections at the harness connector of the headlamp dimmer switch. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 10 | Go to Step 9 |
| 7 | 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 10 | Go to Step 8 |
| 8 |
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 10 | - |
| 9 | Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal Switch Replacement
in Steering Wheel and Column. Did you complete the repair? |
Go to Step 10 | - |
| 10 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |