Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 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 liftgate latch assembly.
- Connect a test lamp between control circuit terminal 1 and ground.
- Ignition ON, command the liftgate to OPEN by pressing and releasing the liftgate interior control switch. The test lamp should illuminate while commanding the OPEN state.
- 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 liftgate control module.
- If the test lamp is always ON, test the control circuit for a short to voltage, if the circuit tests normal, replace the liftgate control module.
- Ignition OFF, connect a test lamp between the control circuit terminal 3 and ground.
- Connect a 3 A fused jumper wire between the signal circuit terminal 6 and ground.
- Ignition ON, command the liftgate to CLOSE by pressing and releasing the liftgate interior control switch. The test lamp should illuminate while commanding the CLOSE state.
- 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 liftgate control module.
- If the test lamp is always ON, test the control circuit for a short to voltage, if the circuit tests normal, replace the liftgate control module.
- If all circuits test normal, test or replace the liftgate latch assembly.