2008 GMC Yukon Owner's Manual - Page 112

To open the entire liftgate, press the touchpad on the underside of the liftgate handle (B). The vehicle must be in PARK (P) to open the liftgate. To close the liftgate, use the pull cup or pull strap as an aid. The liftgate or liftglass cannot be opened if the rear wipers are in motion. Attempting to open the liftgate or liftglass while the rear wipers are in motion will cause the release of the liftglass or liftgate to delay until the wipers are moved off the liftglass. Both the liftglass and liftgate have an electric latch. If the battery is disconnected or has low voltage, the liftglass and liftgate will not open. The liftglass and liftgate will resume operation when the battery is reconnected and charged. On vehicles with a liftglass, press the button on the underside of the license pocket applique (A) to open it. The liftglass can also be opened by pressing the liftglass release button on the RKE. If the battery is properly connected and has adequate voltage, and the liftgate or liftglass still will not function, your vehicle should be taken to a dealership for service. 2-14