From a thread over on the Sol side, reproduced for your reading pleasure
The way the trunk release works is when you push the trunk open button, a relay releases both the buttresses by moving the locking wires AND a cable pulls on the trunk latch release.
The two buttresses are the "wings" that continue the line of the top on each side back to the trunk lid. The two holes in the trunk with the chrome trim rings are the buttress holes. Inside the two buttress holes you can see a locking wire that engages the slot on the buttress lock. It looks like a small arrow head on the end of each of the buttresses and is pressed into the buttress hole when putting the top up.
There is a cable that is Y shaped that goes from an actuator (electromechanical device that pulls on the cable) to each of the buttress locking wires. The Y cable moves each of the buttress locking wires to the inside of the car and releases the buttress locks. There are springs in each of the buttresses that cause them to pop up and rotate forward to the retracted position. If one of the buttresses does not pop up but the other does, that is a good sign that the end of the Y cable that releases the buttress locks has failed. This can be repaired in one of two ways. First, by replacing the Y cable, and second by repairing the end of the Y cable that has failed. The end of the cable have plastic fittings that over time can fail. This plastic fitting can be replaced with a crimped fishing weight. There is an earlier post in this thread that describes this repair. Its pretty simple and easy to do.
If the buttresses DO pop up (retract) but the trunk does not open, that can be due to a sticking trunk, failed torsion bars - there are two torsion bars behind the trunk lid that act against lever arms on the hinges and open the trunk. They can rarely fail by breaking. Many have torsion bars that are weak and occasionally the trunk lid will unlock but will not pop open.
You can check the operation of your trunk release by pushing the trunk open button on your fob and pulling up on the trunk at the same time. If the trunk lock releases you should be able to pull the trunk open.
It is possible that there is an obstruction in the trunk lock that is causing it to not release. I have seen people get micro fiber towels into the trunk lock and it clicks but will not release. If you have this condition then you need to get a friend and both pull up while activating the release button.
It is possible that the trunk lock is NOT releasing. There is a special cable set that includes the relay and cabling that pulls on the trunk lock to release it. If that relay is not activating, it can be because of a fuse or other electrical problem or worst case the relay has failed. If it has failed, then you need to manually unlock the trunk.
There are a couple of ways to manually release the trunk lock. The "GM" way is to jack up the left rear wheel, take off the tire/wheel, remove the inner fender and cut a hole through the trunk side, or go through the trunk pressure release valve so you can reach inside the trunk and pull the emergency manual trunk release. This is a relatively simple but non-trivial job to do.
The other method is you can go in through the drivers side "flap" that rotates up when the top goes up and if your arm is skinny enough, you can reach inside and manually pull on the lock and release the trunk.
I have not done this personally but have read about it on this forum. I recommend that if the trunk lock is not releasing, you borrow a friends car and look carefully at the locking mechanism and practice manually unlocking it while you can see what is in there, then do it to your car.
Once you have your trunk open you should be able to visually inspect the trunk lock and see if it has failed or if there is some other problem.
Here is a site with drawings and part numbers that may help visualize how things work.
2008 Pontiac Solstice Rear Compartment Hardware, Part 2 - 2M1201901LNFM822MB67
In this picture, part #19 is the cable assembly that releases the trunk lock. This cable assembly is part number 15896556 CABLE R/CMPT LID LAT REL,(R/CMPT LID REL ASM W/REL HANDLE)
Replaced by: 25984475
If you look carefully, you will see that this cable assembly continues over and connects to #9 the Y cable that releases the two buttresses. This Y cable is part number 15805321 CABLE R/CMPT LID LAT REL,(INCLS 7)(PART OF 12),(BUTTRESS REL CABLE ONLY)
Replaced by: 25980845
When you push the button on your key fob to open the trunk, a coded radio signal is sent to the car's receiver. The receiver tells the BCM that the operator wishes to open the trunk. The BCM then generates a command to the #19 cable assembly relay that activates it and opens the trunk. Anything that interrupts this command path can be the problem. Check the easy things first. Fuses, power to the car, listen for the cable assembly relay to click near the center of the trunk and observe if the buttress locks are moving toward the center of the car. If you see the buttress locks moving away from the buttress holes (look into the hole with the chrome rings around them in the trunk) then you know that the relay is working. If the trunk is still not opening, then the problem is in the lock cable or lock mechanism for the trunk. Most likely it has an obstruction in there.
This old thread also provides an alternative method for manually opening the trunk using the emergency release handle
Easy Fix for Complex Problem: Manual Trunk Lid Pull
09-15-2006, 03:16 PM #1 (permalink)
Join Date: Dec 2005 Easy Fix for Complex Problem: Manual Trunk Lid Pull
For you people that have been worried about the power going off to the automatic trunk lid opener, the button in the key fob or the glove box not
working or if you have an electrical malfunction, here is a simple answer to
Do the following:
1. Put top down in trunk and lean driver's seat forward, exposing seat belt slot where it comes through back wall at top of cabin.
2. Locate the Emergency Trunk Release Handle (ETRH).
at top of front, inside of trunk almost directly below top of crown behind
driver's seat and locate a motorcycle type of cable with white locator in clip-on support with about 2 inches of inside pull wire that goes to a black lever.
4. Pull manual ETRH to make sure you have the correct lever. When ETRH is
pulled, you will see lever move about 1 1/2 inches. At this point you will need
the following parts: Twenty inch piece of wire that is normally used to hang a
picture, large split ring that is used for holding keys, electrician's tape to
cover twisted wire ends and wire cutting pliers.
5. Bend about 2 inches of wire back on end of 20 inch wire forming a hook. Pull split ring into wire hook and twist small end around long wire several times to secure split ring to end of wire. Wrap twisted end with a few turns of electrician's tape.
6. Run other end of 20 inch wire through seat belt slot and route up and around brace and other cable part over on top of clip that holds white end of motor-cycle cable. Thread end through top or lever that holds end of motorcycle inner cable. How the 20 inch wire is run is very important. You may have to
try it a couple of times until it pulls lever easily.
7. Make sure you have a couple inches of wire left on split ring end of wire inside of seatbelt slot.
8. Bend end of wire that has been run through lever back over top of lever and twist around long part of wire several times and cut off excess and tape.
9. Close trunk lid and pull split ring and make sure it works. Then try with top up, trunk lid closed and bolsters in their holders.
10. If wire has been routed correctly, the trunk lid shoud open when pulled.
This is not at all complicated and I hope I have adequately described the
procedure. It sure beats GM's suggested removal of left rear tire, etc. Also, it is strongly suggested that you do not pull the split ring while cruising down the highway at 100 mph.
NOTE: ETRH WILL NOT RETURN ON ITS OWN. Make sure you have returned it manually each time you use split ring pull so trunk will lock completely. For additional information or digital pictures of procedures, e-mail me at [email protected]
Charles, No-slack, Powers