Can you get the liftgate open at all? If not, you will have to use the liftgate trim panel plug to open it and then remove the liftgate trim panel to inspect the latching mechanism. Try lubricating the latch with WD40 and see if that helps the issue. To access the plug you will have to locate the dimple on the trim panel. Use a 1 1/16" drill bit to drill a hole through the trim panel in the dimple area. Use a flat blade tool (i.e. screwdriver) to push down on the black bellcrank lever through the plug hole to unlock the liftgate. Push open the liftgate from the inside. Pic below shows where dimple should be (where to drill)
November, 8, 2010 AT 9:25 PM
Lift gate will open manually. Can I check the motor, it doesn't seem to run. Possibly a relay or control module?
November, 8, 2010 AT 11:04 PM
Okay, well that's good. Since the gate is open you can easily remove the trim panel to access the motor. Before doing this though, you can check the fuse labeled LCK2 (15 amp), OBS DET (10 amp) and UNLCK2 (15 amp) all in the instrument panel fuse block located at the left side of the instrument panel behind the access panel. If these fuses are good then the liftgate release relay may be bad, unfortunately this is a printed circuit board (PCB) relay which means it is built into the fuse block, so if it is bad the entire block must be replaced. You said you hear a noise when pushing the button though, so I would assume that is the relay clicking. You can test the motor by supplying 12v direct power to it from a 12v source (i.E. Spare car battery). With 12v direct power and a ground, the motor should run without using a switch. If it doesn't run this way it is bad, if it does run then power is not getting to it.
August, 8, 2012 AT 2:37 PM
I am experiencing the same problem on my 2007 Yukon Denali XL. When I push the button on the remote I hear the lock motor disengage, the lights flash and the gate releases but won't power up. If I manually release and open the gate the struts will hold it up so I don't feel they are bad.
When opened manually if I try to close it with the remote the lift motor starts then stops. This tells me the motor is getting 12v, and I have checked the recommended fuses as well.
Is the motor weak? Does it have a protect circuit that shuts it down? I am not sure which way to look from here.
October, 26, 2012 AT 8:07 PM
I also am experiencing the same EXACT problem, and if one more person asks me if it's the "button" turned off I will scream! Rear access door will open manually, but when keyfob is used it only tries to work, I can hear the motor coming on but door will not open on its own, when its opened manually it will stay open, so its not the struts. Anyone ever find a solution?