One problem related to tailgate has been reported for the 2006 GMC Envoy. The most recently reported issues are listed below.
The tailgate will occasionally not open. The actuator has already been replaced. The electrical system seems to also "act"up when this happens. The remote takes several times to open the doors. We have replaced the battery several times, the dome light does not come on anymore, the stereo turns off immediately when you turn the engine off, instead of staying on until you open one of the doors.