Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
- Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 8.
- If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
- Verify the scan tool Rear Fog Lamp Switch parameter displays Inactive.
- If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the XBCM.
- Install a 3 A fused jumper wire between the signal circuit terminal 6 and the ground circuit terminal 8. Verify the scan tool Rear Fog Lamp Switch parameter is Active.
- 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 XBCM.
- If all circuits test normal, replace the headlamp and panel dimmer switch.