Diagnostic Aids
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.
Power liftgate function will only be allowed if certain operating criteria are met. Any of the following may cause the power liftgate not to function:
- Vehicle is not in park
- System voltage is below 10.5 V
- Engine is cranking
- The vehicle doors are locked
- A liftgate control module DTC is set
- Liftgate motor excess current is detected which may be caused by a misaligned liftgate striker
- Interior trim and/or liftgate wedge/bumper misalignment
Whenever the liftgate control module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate control module.
An open or shorted accessory wake up ignition circuit between the engine control module and transmission control module will cause the power liftgate to work when the ignition is ON but not work when the ignition is OFF.