Diagnostic Aids
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.
Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power for the appropriate procedure.
If the vehicle has a history of the liftgate opening unexpectedly, inspect the point where the wires enter the exterior liftgate handle switch for corrosion or evidence of water intrusion.