2002 cadillac deville trunk & fuel filler door won't open from inside

check for blown fuse for int. lamps, locks fuse and 2 relays. do any locks work?

1) Key turns but dose not unlock door. This means that the rod that goes to the back of the lock has came off. This also means that is the reason door is not unlocking with the remote as it pops the lock rod inside the door which pushes the lock open.
2) Key does not turn lock at all but works passengers side door. This means that the locks has been changed in the door, but that doesn't sound like the problem as you say the remote doesn't open the drivers side door so more than likely the rod has came off the back of the lock

Should be a release in the trunk. Check your owners manual.

Fixed. In the glove box there is a vallet button. I pushed it and now my trunk and fuel door work. and what this has to do with my trunk and fuel door not functioning , I have no idea. Hope this helps someone else.

the K134 relay is a multifunction relay the controls the proper operation of the radio, fuel door, and the trunk. As far as I can tell the A/C is a separate issue and the check engine is most likely related to the relay being bad.

Hello: Open the glove box on passenger side of dash and check the valet switch., if it is on that will keep the trunk and fuel door from working. Shut the valet switch off

Hello: Please check the valet switch in the glove box if it is on, turn it off and try the trunk and fuel door. Also there are 2 fuses for this system. The fuses are in the trunk compartment fuse block. They are labeled as follows:radio/phone fuse 10 amp and convenience fuse 20 amp. The round key should open the trunk, if not then it might be the wrong key or the trunk lock cylinder may have been replaced.

There should be a cable in the trunk for a emergency release

This happened to me, someone had accidentaly switched the button inside the glove compartment to lock, which locks everything except a few items for the Valet key, keeping trunk, locks and fuel door closed until that silly button is put back in original unlocked position. Goofy, but I suppose it's a good feature for some, sure had the Cadillac guy concerned for about ten minutes until he remembered that stupid lock out option inside the glove compartment!

let me assume u have not checked the fuses, meaning in al places the fuses are!, try,under the hood,under the dash and behind the panel behind the rear seat in the trunk, look in your owners manual for these locations and the particular fuse u have trouble with. good luck,hope we helped!