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Last Month my trunk wouldn't open electronically with any of the release buttons but only mechanically with the key behind the license plate. It persisted for over a week so I scheduled an appointment to have it looked at. All of a sudden out of nowhere it began to work so i cancelled the service appt.. Now again it is happening but even the manual key release behind the license plate wont work. Has anyone had this experience? I know a couple of other people had the issue but at least the manual key release was working for them.
^^^
Mine would only open with the manual key. It's not easy to turn but it opened. Dealer tech found a corroded terminal and since that wiring harness was attached to the assembly, ordered a new one. Fixed and has worked fine for ~5 months.
Can see corrosion being intermittent. Don't know why the key is not working, it mechanically pulls the latch.
^^^
Mine would only open with the manual key. It's not easy to turn but it opened. Dealer tech found a corroded terminal and since that wiring harness was attached to the assembly, ordered a new one. Fixed and has worked fine for ~5 months.
Can see corrosion being intermittent. Don't know why the key is not working, it mechanically pulls the latch.
Thanks, I had actually stumbled upon your post the first time it happened. This time the key wont open the release. The only thing I could imagine is that it is jammed somehow. If I turn the key any harder it will snap. Im going to have to find a decent service center to take it to.
Have you tried pressing down on the hatch while turning the key? Possible that there is upward pressure being exerted against the latch mechanism. If that is the case the latch mechanism would require extra effort to open. Of course the latch mechanism could simply be defective and need replacement.
Thanks, I had actually stumbled upon your post the first time it happened. This time the key wont open the release. The only thing I could imagine is that it is jammed somehow. If I turn the key any harder it will snap. Im going to have to find a decent service center to take it to.
Boy, won't be easy to get to the latch without the hatch open!
Understand with the key. Had same issue when I tried to open the door. Used plyers so the key didn't break off from the FOB! Good luck, keep us posted.
Have you tried pressing down on the hatch while turning the key? Possible that there is upward pressure being exerted against the latch mechanism. If that is the case the latch mechanism would require extra effort to open. Of course the latch mechanism could simply be defective and need replacement.
Thats a good thought, I tried that while attempting the electronic release but not when using the manual release. Ill give it a shot!
No luck, car is still at service and they cannot get the trunk open. They are saying the only way is to use a holesaw and drill a hole into the trunk to gain access. They also do not believe me that I am not the only one having an issue with the rear trunk opening as they claim GM has no records of this happening before.
Any suggestions would be appreciated, if they have to destroy the trunk then who knows how long it will take to get a replacement.
Last edited by nofinga911; 11-08-2021 at 02:37 PM.
Please, if anyone has any suggestions I would be happy to hear. Service and GM are saying the only way is to cut a 3 inch hole in the trunk to gain access. Theres got to be another way. They may not even cover the work and repair depending on what they find/ what caused failure when they get it open. Yes, its a disaster.
I provide this response with no actual first hand knowledge of C8 trunk operation, but have had similar trunk problems with other cars. I just don't want them to have to cut a hole in your trunk man. I'm sure they may have already done these things suggested below, but might be worth it to verify.
2. WD 40 the **** out of the lock opening and the key, Insert key, gently tap key (with like the handle of a screwdriver or something) while turning to unlock
4. Lastly, is there release cable that runs to the trunk of a C8? Is there a way to access the cable from the interior by removing panels/seats etc (I've had to do this on a vehicle before with a locked trunk, and pull the cable with vice grips using everything I had)
Houdini Lock Lubricant is what I used once on a car key lock. Now my situation was different. It was winter and I locked this car at a fast food place. I came out and the key would not open the door or the trunk. Called lock smith. He came out and I told him the problem. He got out his can of spray and sprayed the lock and the key. Inserting the key several times as he sprayed the key. He did all the key locks and the trunk. They worked perfect. Now my locks were not working prob. because of age and dirt.
But you said you were desperate. So I throw this out. A $10 can of spray. Never know.
I now yearly treat all my car and house locks with this spray to keep them is working condition.
Have they tried using a plastic or metal pry bar on the sides or back of the trunk to move it one way or the other. This might relieve some pressure that is keeping the latch for releasing.
Last edited by Nelag; 11-11-2021 at 01:15 AM.
Reason: Just adding an idea.
I provide this response with no actual first hand knowledge of C8 trunk operation, but have had similar trunk problems with other cars. I just don't want them to have to cut a hole in your trunk man. I'm sure they may have already done these things suggested below, but might be worth it to verify.
2. WD 40 the **** out of the lock opening and the key, Insert key, gently tap key (with like the handle of a screwdriver or something) while turning to unlock
4. Lastly, is there release cable that runs to the trunk of a C8? Is there a way to access the cable from the interior by removing panels/seats etc (I've had to do this on a vehicle before with a locked trunk, and pull the cable with vice grips using everything I had)
Sorry, that's all I got
The tech claims he tried everything but I also brought up the lubrication to him and he stated he wouldn't be able to get it to the latch as there are obstacles in the way. I cant remember exactly how the layout is on the inner side of the trunk and if there would be a straight route directly to the latch.
Is there not a emergency release cable inside the trunk (incase get stuck inside)? That is the cable I was able to pull by removing panels inside one of my vehicles.
^^^
The emergency cable is a key cylinder behind the license plate that pulls a cable. NOTHING in the cabin.
I had a similar problem and used the mechanical key on the FOB. However like the mechanical latch to get in the trunk and car (inside the rear fender driver's side scoop) are HARD TO TURN. Since I had to open the trunk a number of times that way before it was fixed, I used a needle nose pliers on the mechanical key so as not to break the joint on the FOB cap.
Tech found my problem was a corroded terminal on the multi terminal plug. Why it corroded, don't know. Could that be the OP's issue - possibly.
Here are some pics of what the Tech had to do. NOTE the plug pic is NOT the one on the car- don't have pic of it BUT saw the corrosion on one terminal. Been working fine for 6 months.
Tech pulled the rear trunk liner back making the latch/motor pull down visible.
He found a corroded terminal that was causing the solenoid not to release the latch. Fuses were fine, Frunk opened fine. These are the key locks to access the trunk and driver's door. Both are hard to turn as they are pulling cables. I grabbed the metal key with pliers so the pin joint attaching it to the FOB cap did not break.
I believe the C6DRYVR might have ment to remove panels in the wheel well or someplace else to be able to reach the trunk release handle that every car is now requited to have for safty reasons. Pull that handle and open the trunk instead of cutting 3 inch hole.
^^^
The emergency cable is a key cylinder behind the license plate that pulls a cable. NOTHING in the cabin.
I had a similar problem and used the mechanical key on the FOB. However like the mechanical latch to get in the trunk and car (inside the rear fender driver's side scoop) are HARD TO TURN. Since I had to open the trunk a number of times that way before it was fixed, I used a needle nose pliers on the mechanical key so as not to break the joint on the FOB cap.
Tech found my problem was a corroded terminal on the multi terminal plug. Why it corroded, don't know. Could that be the OP's issue - possibly.
Here are some pics of what the Tech had to do. NOTE the plug pic is NOT the one on the car- don't have pic of it BUT saw the corrosion on one terminal. Been working fine for 6 months.
Tech pulled the rear trunk liner back making the latch/motor pull down visible.
He found a corroded terminal that was causing the solenoid not to release the latch. Fuses were fine, Frunk opened fine. These are the key locks to access the trunk and driver's door. Both are hard to turn as they are pulling cables. I grabbed the metal key with pliers so the pin joint attaching it to the FOB cap did not break.
So when the tech told me he got the trunk lifted enough with an air bladder, to pull the emergency release cable (which he states snapped), he has to be lying. If the only release cable is attached to the lock cylinder then he would not have been able to access it through the trunk since it would be behind the trunk paneling. Am I correct?
Also, I suggested for them to spray a lubricant over the latching mechanism since they are able to lift the trunk a bit with the air bladder but they told me due to the way the trunk is shaped, there is not a straight route to get to the latching mechanism and there are obstructions in the way. Without having my trunk open to check this, I cannot recall. Can anyone attest to this? Would it be possible to get a lubricant straw or hose to the latch if the trunk was slightly lifted/pried?
I believe the C6DRYVR might have ment to remove panels in the wheel well or someplace else to be able to reach the trunk release handle that every car is now requited to have for safty reasons. Pull that handle and open the trunk instead of cutting 3 inch hole.
Correct. I'm not sure if there is one routed in the C8. I removed panels and a speaker in a vehicle once and was able to pull the emergency release cable with vice grips where it was routed underneath and passed by. Worse comes to worse, hopefully they can drill behind where the license plate mounts.
the hatch contains the metal loop that is retained in the hatch and pulled closed by the latching mechanism which is attached to the main body of the car. Replacing the hatch will not change the issue of a possibly defective latch mechanism.
10-20-2021, 01:12 PM
2020 C8 Trunk Wont Open
