Lift-gate will not electrically open or close

Tiny
LES CARSON
  • MEMBER
  • 2007 GMC YUKON

V8 front wheel drive automatic 49,000 miles.

Lift-gate will not open or close electrically. There is a sound when initiated but gate quits not lifting or closing.

Lift gate will open manually. Can I check the motor, it does not seem to run? Possibly a relay or control module?

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Monday, November 8th, 2010 AT 7:56 PM

4 Replies

Tiny
BLUELIGHTNIN6
  • EXPERT
  • 16,892 POSTS

Hello and thanks for donating

You will have to use the lift-gate trim panel plug to open it and then remove the lift-gate trim panel to inspect the latching mechanism. Try lubricating the latch with WD40 and see if that helps the issue.

Since the gate is opening manually 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 lift-gate 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 twelve volts direct power to it from a twelve volts source (i.E. Spare car battery). With twelve volts direct power and a ground, the motor should run without using a switch. If it does not run this way the motor is bad, if it does run then power is not getting to it.

If the lift-gate is not opening manually 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 bell-crank lever through the plug hole to unlock the lift-gate. Push open the lift-gate from the inside.

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Monday, November 8th, 2010 AT 11:04 PM
Tiny
N2TRUX
  • MEMBER

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 will not power up. If I manually release and open the gate the struts will hold it up so I do not 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 twelve volts, 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.

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Wednesday, August 8th, 2012 AT 2:37 PM
Tiny
CANDICETURNBOW
  • MEMBER

I also am experiencing the same exact problem, and if one more person asks me if it is the "button" turned off I will scream! Rear access door will open manually, but when key-fob 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 it is not the struts. Okay, so I have the same problem. I took it to a shop and they replaced the motor assembly, the rear ECU (electronic control unit), the electric latch (which was working when I brought it in), and the BCU (body control unit) which is basically the computer that controls all the functions of the vehicle other than the engine. After all was said and done, the gate opened only part way and when I pushed the button to close it, it went partly way down and back up again. That was last week. This week it is back to manual opening only, exactly what it did before I took it to the shop. Anyone ever find a solution?

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Friday, October 26th, 2012 AT 8:07 PM
Tiny
KEN
  • ADMIN
  • 12,935 POSTS

Hello,

What happens in these cars is the liftgate motor starts to go bad causing the amperage to be higher than the electronics are designed for so it burns them up there is also a control module that works the system as well.

Here are the wiring diagrams and repair manual diagrams to help you see how the system works. It sounds like the liftgate module is bad.

Check out the diagrams (Below)

Please let us know what happens.

Cheers, Ken

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Tuesday, December 19th, 2017 AT 5:21 PM

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