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 inside rearview mirror.
- Doors closed, courtesy lamps OFF, test for less than 10 Ω 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, command the green LED OFF with a scan tool. Test for less than 1 V between the control circuit terminal 14 and ground.
- If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the CIM.
- Command the green LED ON with a scan tool. Test for greater than 9 V between the control circuit terminal 14 and ground.
- If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CIM.
- Command the red LED OFF with a scan tool. Test for less than 1 V between the control circuit terminal 15 and ground.
- If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the CIM.
- Command the red LED ON with a scan tool. Test for greater than 9 V between the control circuit terminal 15 and ground.
- If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CIM.
- If all circuits test normal, replace the inside rearview mirror.