Headlamps Inoperative - Low and High Beams
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Headlamps Inoperative - Low and High Beams
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views |
|||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
|
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
| 3 | Are both high and low beam headlamps inoperative? | Go to Step 4 | Go to Headlamps Inoperative - Low Beams (High Intensity Discharge (HID)) or Headlamps Inoperative - Low Beams (Standard) or Go to Headlamps Inoperative - High Beams |
| 4 | With a scan tool, observe the headlamp switch data parameter in the body control module (BCM) data list. Does the scan tool indicate ACTIVE? |
Go to Step 7 | Go to Step 5 |
| 5 | Connect a test lamp between the ground circuit of the headlamp switch connector and battery positive voltage. Does the test lamp illuminate? |
Go to Step 6 | Go to Step 9 |
| 6 | Test the headlamps switch headlamps on signal circuit of the headlamp switch for a high resistance, an open, or a short to voltage. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
Go to Step 12 | Go to Step 8 |
| 7 | Inspect for poor connections to the BCM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 12 | Go to Step 10 |
| 8 | Inspect for poor connections to the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 12 | Go to Step 11 |
| 9 | Repair the ground circuit of the headlamp switch. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 12 | - |
| 10 | Replace the BCM. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
Go to Step 12 | - |
| 11 | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Did you complete the replacement? |
Go to Step 12 | - |
| 12 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 3 |