1995 GMC Yukon Owner's Manual - Page 109

Electric Tailgate Glass Release Before operating your electric tailgate glass release, see the caution under "Tailgate Glass, Tailgate and Rear Doors" in this section. The electrichatch release button lets you release the tailgate glass. To release the glass, press the top of the switch button. Then, lift thewindow up to open. If you have an automatic transmission, your shift levermust be in PARK (P) or NEUTRAL (N) for the release to work. With a manual transmission, you must apply the parking brake for the release to work. 2-37