GM Service Manual Online
For 1990-2009 cars only

Rear Liftgate Release

The liftgate can be released by operating the liftgate release switch. The gear selector may be in any position, but the doors must be unlocked and the vehicle must be stationary for the liftgate to release.

Pressing the liftgate release switch closes a contact providing a ground for the liftgate release switch signal circuit. The body control module (BCM) will detect the voltage drop and command a ground to be supplied to the liftgate release relay control circuit thus energizing the L/GATE RELSE relay which provides voltage to the liftgate latch. When the doors are locked, the BCM will disable the liftgate release system by ignoring the liftgate release switch input command and not providing a ground for the L/GATE RELSE relay.