Recently I had to use my trunk key for the first time. I had to "work it a bit" (jiggle, twist, etc.) quite a bit for the key to fully insert so I could unlock (open) the trunk. Hope this helps.

 

The key should open the trunk. Try squirting some graphite in the key hole to clean it up. They get dirty from the road and are hard to open. Even when it is clean, you have to turn the key harder than you would think to get the hatch to pop open

 

 

Did you turn it 5 times in less than 5 seconds? I reprogramed a new fob about a month ago and the first time it did not work...I think it was because the drivers door was open,,,,Tried it again with door closed and window down and it worked.....Good Luck

 

Yes, key needs to unlock trunk. That's how you get in car if fob, receiver or battery dies.

 

Trying cleaning the key cylinder cause it fills with dirt, after you get it clean, and working, cut a piece of duck tape, and seal it off from dirt.

 

It is possible that the key is turning the tumbler, but if the cable is unhooked from the latch, it won't open the truck.
Also, if you have the Coupe, and the cable is unhooked, it will not allow you to program the FOB>

I've attached some info from years ago.

 

Since the key will turn, pull the back panel to start with that is covering the latch assembly, so you can look the cylinder assembly end cable to the latch assembly and make sure it clipped in place, and that the cable is being drain as you do turn the key.


And not like this,




Next, we get into how the car sees the key being turned all the way over.
On some models, the cylinder has a set of wires coming off it for the full key turn switch, while on other modules, the wires are coming off the latch instead.
So what is need to to check to see if the problem is the connector not plugged in, or a problem with the switch when the key is turned if cylinder switch /latch switch isntead.


As for if the problem is the cylinder assembly, do not be a rush to replace it. Hence if you can pull it apart to correct the problem do that instead. If you replace the key cylinder assembly (drill out the rivets to rivet the new one in) it not sunshine type event. Hence new cylinder is going to be keyed for something else, so you have to take the assembly down to a lock smith to remove the cylinder from the plate and re-pin the cylinder to work with the key that is tied to the Vin number of the car.
This way, if you do lose the key, GM can pull the vin number to cut you a new key.

If your in the Denver area, can give you a hand to make sort work of solving the key/latching problem to begin with, and since I do have a tech II, can make short work of programming in the new fobs without having to play the waiting game putting the car into fob re-lean mode with the key instead.

 

push down on the trunk lid when turning the key will sometimes help relieve the pressure that is holding it from opening.

 

I vote to try this ^^^^^. My key needs to be turned really (careful you don't brake the key) hard against the stop. Turns easily but nothing happens. I never thought that could truck lid could be the problem.