Dome/Interior Lamp Switch Malfunction
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the headlamp switch.
- Test for less than 5 ohms between the ground circuit terminal 8 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Ctsy. Lamp Actv. Reason parameter is Off.
- If the scan tool parameter is Manual or Manual Defeat, test the appropriate signal circuit terminals for a short to ground. If the circuit tests normal, replace the BCM.
- Manual terminal 12
- Manual Defeat terminal 9
- If the scan tool parameter is Manual or Manual Defeat, test the appropriate signal circuit terminals for a short to ground. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the signal circuit terminal 12 and the ground circuit terminal 8. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual.
- If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the signal circuit terminal 9 and the ground circuit terminal 8. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual Defeat.
- If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
- If all circuits test normal, test or replace the headlamp switch.