Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Each courtesy lighting component may need to be disconnected to isolate a short to voltage or short to ground. Use the schematic to identify the following:
- Courtesy lighting components the vehicle is equipped with.
- Component locations on the courtesy lighting control circuit
- Each component's control and ground circuit terminals
- Ignition OFF, disconnect the harness connector at any component with inoperative courtesy lighting.
- Ignition OFF, scan tool disconnected, interior lamps OFF, doors CLOSED, test for less than 5 Ω between the ground circuit and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a test lamp between the control circuit and ground.
- Command the Courtesy Lamp control ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
- If all circuits test normal, replace the component with the inoperative backlighting.