2000 GMC Envoy Owner's Manual - Page 71

Liftgate/Liftglass CAUTION: It can be dangerous to drive with the liftgate or liftglass open because carbon monoxide (CO) gas can come into your vehicle. You can't see or smell CO. It can cause unconsciousness and even death. If you must drive with the liftgate or liftglass open or if electrical wiring or other cable connections must pass through the seal between the body and the liftgate or liftglass: D Make sure all other windows are shut. D Turn the fan on your heating or cooling system to its highest speed with the setting on OUTSIDE AIR. That will force outside air into your vehicle. See "Comfort Controls" in the Index. D If you have air outlets on or under the instrument panel, open them all the way. See "Engine Exhaust" in the Index. Liftgate Release To release the liftgate or liftglass, you may use your power door locks or the keyless entry system described earlier. The liftglass can be opened using the pushbutton on the liftgate after the driver's door has been opened using either the power lock system or the keyless entry system. To open the entire liftgate, unlock the doors using either the power door lock system or the remote keyless entry system and lift the handle located in the center of the liftgate. 2-9