Interior Backlighting Circuit Test
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 affected component.
- Ignition OFF, verify that a test lamp illuminates between the listed ground circuit terminal and battery voltage.
- Passenger window switch terminal F
- Headlamp switch terminal 8
- Transfer case control switch terminal 6
- Sunroof switch terminal 5
- Door lock switch terminal B
- Roof beacon switch terminal 1
- Sliding rear window switch terminal D
- Garage door opener switch terminal 3
- Outside rear view mirror switch terminal G
- Driver window switch terminal A X2
- If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
- Connect a test lamp between the listed backlighting control circuit terminal and ground.
- Passenger window switch terminal B
- Headlamp switch terminal 7
- Transfer case control switch terminal 5
- Sunroof switch terminal 3
- Door lock switch terminal A
- Roof beacon switch terminal 2
- Sliding rear window switch terminal E
- Garage door opener switch terminal 2
- Outside rear view mirror switch terminal E
- Driver window switch terminal 1 X1
- Command the dimming test high to low with a scan tool. The test lamp should turn from bright to dim when changing between the commanded states.
- If the test lamp is always off, test the control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the BCM.
- If the test lamp is always bright, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
- If all circuits test normal, test or replace the affected component.