2004 GMC Envoy XUV tailgate won't open downward. Tailgate will swing open but will not open downward. Nothing happens when pressing in on pressure pad/switch...it is as if there's no power going to it.

Do you live in a dusty area? My sister lives in dusty New Mexico and had a malfunctioning XUV tailgate. My reasoning was that something must tell the tailgate not to drop down if the glass is up, and if it can't tell, then it will only open sideways.
So we removed the trim panel, and the tailgate was indeed full of dust. By reaching my arm in, I found two plastic optical sensors which tell the gate whether the glass is up or down; both were coated with dust. After cleaning these the tailgate was back to its normal operation. The two sensors are flat, round - about the size of a nickel or dime...I couldn't see them, just found them by guessing that they must be there. Hope this helps!

I know this is an old post but this is just in case anyone runs into the same problem. My tailgate recently started doing the same thing. It would swing open but not fold down. When I would press the yellow switch inside the cargo area you could hear a low click but nothing. Also the tailgate would some times not latch shut either. I tried the solution above but it didn't work for me. What I did was;

1. I got some of my throttle body cleaner and sprayed just a little bit on the latch and used an old toothbrush to clean out any gunk that might be making the latch stick.
   
2. After it dried then I sprayed the latch with WD-40.
   
3. I did the same with the top latch on the passenger side. This helped the tailgate to latch shut.
   

1. I keep the tailgate firmly pressed against the vehicle.
   
2. Squeeze the switch on the tailgate and hold, you will hear the first latch release.
3. Keep pushing the tailgate against the vehicle and keep squeezing the switch until you hear the second latch release and the tailgate should fold down.

It appears that both of the left side latch actuators are working, since you can swing it open. one you have it open, look over at the top of the right side, where the upper hinge is, and you will see the top of the right side latch actuator where you will find a small hole exposing the manual latch trigger. reclose the tailgate, and with a long thin screwdriver, trick-out the manual latch trigger while pressing the Power Tailgate Release Switch. that should open it, but you still might have a problem with the releasing mechanism in the right hinge. Spray it down with some WD-40 and see if you can get it to operate by closing the latch with a screwdriver shaft and exercising it. none of the latch actuators are available from GM an more, so you will have to find one from a salvage yard, although many of the mechanisms look alike, the mounting is totally different.

Is there any good pictures of the manual switch to open the liftgate