ChopTop is right on.
The trunk mechanism consists of a cable assembly that is mounted to the front trunk bulkhead. When you have the trunk open, stand on the left side of the car and look at the front of the trunk. You will see the cable assembly there. It has multiple electrical connectors plugged into it and it is right below the tulip panel.
The BCM commands a set of relays that are part of the cable assembly. Its #19 in the attached drawing.
The cable assembly is connected by a cable to the trunk lock. #14 in the drawing. When the button is pushed, the trunk lock is released by a relay on the cable assembly.
The cable assembly is also connected to the buttress locks, one left and one right. In the drawing you can see a cable snaking to the right as part of the cable assembly and connecting with the T cable that imparts the motion to unlock the two buttress locks inside the trunk lid.
If when you push the button to open the trunk one of the buttresses does not release, it is probably the cable end connector - a plastic part - that has failed. Once you get the trunk open by manually releasing the offending buttress, you can gain access to the release cable end by prying down on the trunk lid cover (fabric material over plastic). There are a couple of threads with instructions and pictures showing how to repair the buttress cable end connector. One method is to use a split lead fishing weight and crimping it onto the end of the cable - works very well. The other method is to buy a new factory plastic end connector and installing that. A worse alternative is to get a new T cable. Costs more and you have to remove and reinstall the cable.
If after you get the two buttresses released, the trunk still is not opening, then it is a failure in the relay or the cable at the cable assembly.
I have never seen any member state that the trunk release lock has failed. All failures I have seen to date are one of the buttress end conecters.
Let us know what your exact problem is and maybe we can offer better help.:thumbs: