View Full Version : Trunk won't open

12-02-11, 07:26 AM
I'm a new XLR owner (what a rush!) with a problem- my trunk won't open. The fob won't work nor will the underdash button. The lights flash and the trunk moves maybe 1/4 of an inch, then goes back down. Any ideas? Thanks.

12-02-11, 09:01 PM
Will it open if you try to retract the top?


12-05-11, 03:42 PM
No, nor will the top open. It starts to engage the top retractor motor, then stops.

Anthony Cundari
12-05-11, 08:22 PM
A couple of questions to establish a baseline and please don't be offended since we don't know what you know:

1. what is the position of the valet rocker switch in the glovebox? on or off? push on the "off" to make it flush to the surface
2. have you ever opened the trunk lid?
3. have you opened the trunk lid using the button on the trunk lid, the dash button or the fob?
4. have you ever lowered the top into the trunk? full cycle to trunk lid closing and car in full convertible mode.
5. have you opened the trunk lid using the key?
added questions:
I'm now making the assumption that the trunk did work and you cycled it.
6. When did it last work? How? as part of the roof opening sequence or trunk lid opening? What button was used?
7. What happened to the car since the last time that the trunk lid opened? Nothing? or, for example, you had a battery failure. Did you store something in the trunk?
8. If you just bought the car, do you have a warranty in effect? If yes, let the dealer solve the problem.

A couple of thoughts:
1. Valet switch "ON" , fob doesn't work, dash button doesn't work, trunk lid button doesn't work
2. Valet switch "OFF", exit car and car locks itself. Window down. Reach in and press dash button and a motor engages, lid moves slightly and the lid stays latched. When I have tried this it sounds like something is going to break and I have quickly unlocked the car to stop it. I don't recommend doing this since I don't know what is happening inside the trunk. This sounds a little like what you are experiencing.
3. Is there something jammed in the trunk? The key will release the trunk lock. You won't see or hear any movement of the trunk lid because it is HEAVY and you will think it is still locked. Take both hands and lift the trunk lid and extend it all the way up (otherwise it will come down on you). If something is jamming the mechanism, you probably won't be able to open it. BTW, if you have had it opened before, anything in the trunk that can jam the mechanism? Be sure to do this in a garage where the car will be protected from rain, snow, etc.
4. Ask yourself "what changed?"

12-08-11, 04:10 PM

If the trunk won't open electrically, there's always the mechanical method for emergencies, but that won't make the problem go away. Most likely, you have one or more faulty sensors. This isn't something you can repair properly in your garage, so you'll need to take it to a Cadillac dealership (make sure they have a Certified XLR Tech or you're inviting more problems) and have it scanned with their Tech 2. The repair is easy with the proper diagnostic tools. Make sure they update the firmware in the Folding Top Control module with the latest and greatest revisions too.


03-04-12, 10:12 PM

The repair is easy with the proper diagnostic tools.


I believe you are mistaken on this point. I have this same problem and have been searching for a solution.

Reading the thread bellow makes the problem sound worse than I had thought

If you bought this car in this condition than this is more than likely the reason for the previous owner selling it

03-05-12, 11:37 PM
The two current XLR stuck latch-related problems being discussed on the various XLR forums at the moment were both made worse by manual release cables that were inadvertantly snapped at the latch and may well have fouled the release mechanism. If the latch is mechanically fouled, supplying an electrical unlatch command isn't going to do any good. Accessing the trunk with a jammed latch (since this is what the emergency key lock cylinder is supposed to open with a loss of electrical power) isn't viable without damaging the rear decklid since the latch is for the most part, inaccessible.

Without further detail, Master Tao's problem (from three months ago) sounds different than yours. I would be interested to know if he had it repaired and discovered the cause. A faulty sensor or decklid open switch will pull the latch back after it is electrically released. (I had the same problem he described last year and it was the decklid Open switch that caused the latch to pop and immediately lock, trapping my fingers and destroying a shot at what might have been a promising piano career.) This is why using the proper diagnostic tool (a Tech 2) makes this problem much easier to troubleshoot.

As I've posted many times, the XLR is not a repair-friendly vehicle for even routine repairs for your average DIY garage mechanic without a Tech 2 and a set shop manuals as a minimum. And no tool is a substitute for mechanical knowledge, specialized training and extensive experience. This is why GM has XLR-certified techs, and they are the best qualified to work on these vehicles. If after doing all the options that have been suggested fail, I would let a certified tech have a crack at it. (No pun intended!)

Yours is not a common problem and unfortunately, in your case, the cure may be worse than the disease.


11-04-14, 06:57 PM
what did Tao eventually do? it just happened on 2005 XLR for the first time


what was Tao's fix? Sounds like others have experienced also. it just happened for the first time on 2005 XLR. The quick open/closing of the trunk prevented putting the top up.

11-04-14, 07:53 PM
This thread was started almost three years ago, with no follow-up regarding his repair/fix. That's the short answer.

Your post isn't clear enough to fully understand your meaning. Do you mean to say your 2005 XLR is experiencing the same symptoms? If so, you most likely have a sensor *there are three) issue. Without a Tech 2, you'll need to have a Cadillac dealer run diagnostics, identify the problem, and make the repair. The module that reads the sensors may need to be re-programmed if the sensor values have changed *or failed) over time. This is easily done and shouldn't cost an arm and a leg.

Some XLR systems are not easily repairable for DIY garage mechanics due to the special tools required. The Tech 2 is one of them.


11-19-14, 02:29 PM
It happened to me once before, put the key in the rear side of the back bumper once you remove the plug with a thin screwdriver, have the wife turn the key and you lift the truck open, its very heavy will need some muscle. Once open, check to see it the cargo storage compartment is snapped in the both ends, if its not that's your problem. Its not making the switch contact. I hope this is your problem, very easy fix. AL

11-23-14, 10:35 PM
The luggage barrier interlock only affects opening of the rear deck lid during operation of the roof, --not the rear deck lid when locally commanded to raise. When commanded to open via fob or rear deck lid release switches on the dash or above the rear license plate, the rear deck lid is supposed to open. In those cases, the rear deck lid OPEN/RAISE command circuit ignores the interlock switch.

When the folding top is commanded to raise/lower, thru the Folding Top Control switch on the center console, the interlock circuit is checked to ensure the interlock switch is closed, otherwise the top can be damaged if the luggage divider is laying flat if there's something large stored in the trunk. If the switch isn't closed, the rear deck lid will not raise and an error message is displayed on the DIC.

A faulty Rear Tonneau sensor can prevent the rear deck lid from opening at any time. If you're having to open the rear deck lid manually, (and it's definitely heavy when fighting the hydraulics) you might want to have the sensor scanned with a Tech 2.