I just noticed today that my fuel door doesn't lock when the doors electronically lock - I think it started doing this fairly recently (but not sure). The actuator is fortunately in the unlock position. The car was taken in to the dealer a couple of weeks ago for the OnStar upgrade (the tech was working in the trunk). Don't know if the failure is related or not. Where do I begin to troubleshoot this problem? Is there a quick place I could check to see if a wire connector has come apart, fuse blown, etc? Or is it possible the solenoid or switch itself has gone out? Does anyone have a GM part number or price for the actuator itself? I know, too many questions, not enough answers !

Thanks.

Carter

There are 2 fuses in the rear fuse block that supplies power to the relays for the fuel door lock solenoid. The ALDL fuse, and the body fuse. You can start by checking those, but I'd expect other problems if they were blown. The schematics show 2 relays, one for locking the other for releasing in the rear fuse block, but I couldn't find those specific ones listed in the diagram for the rear fuse block. They could possibly be relays 47 & 50. F/trnkdr lock and rel relays.

However, I would suggest lubing the mechanism first to see if that helps. It can easily be removed from the outside, after opening the fuel door.

I agree with the above. Lube it up first with some WD-40 and see if that helps. Once in a while my fuel door won't unlock when i unlock my doors, so i have to get into the trunk to pull the cable to get the fuel door open.

Should further troubleshooting become necessary, these are indeed the relays. Each one is controlled by a seperate output of the rear integration module.

Based on my experience with a 2002 SE, I'd have to agree that the most likely cause is corrosion and/or lack of lubrication. Interestingly, these seem to have been discontinued in the 2004-05 cars.