Fuel Door won't lock - 2002 Volvo XC70

[Stephenxc]

Hello.
Recently I had a fuel door that would not lock. I managed to lubricate and blow air into the plunger that locks the fuel door and Thought I had it working. Right now if I unlock the fuel door it unlocks and if I drive away it locks and I can hear an audible locking sound.
When I stop the car the fuel door is locked however when I locked the car with the key fob the car locks the fuel door is open!

I am going to attempt opening the driver side panel in the trunk of our 2002 XC70 and disassemble and clean the motor.

Any advice pictures or videos will be of great help.
Happy new year everyone!

[Sierra]

In my experience it was just much easier to just get a keyed locking gas cap from NAPA for $11.

Put one key on the ring and the spare in the glove box.



From what I understood - You had to have VIDA to diagnose and program to fix it to correctly working order again.

[ebaron]

Are you sure it is not the hinge spring that keeps the door closed? It sounds like your lock is working but the door is swinging open when you turn off the car. I believe it automatically unlocks for 15 min. After car is shut off. This gives you time to fuel the car. The door should only open as you pull it open and there should a little resistance as the spring keeps it shut. There may be a tab on the lid that broke. Hinge is cheap and easy to replace. Check that first.

[hoonk]

Right now if I unlock the fuel door it unlocks and if I drive away it locks and I can hear an audible locking sound.
When I stop the car the fuel door is locked however when I locked the car with the key fob the car locks the fuel door is open!

The gas door does not lock when you lock the car. (immediately) This is to allow you get out, lock and refuel the car with the doors locked and the key in your pocket.

[nickbw]

Either as has been said the flap is not staying flush with the wing, so that when the lock shuts (10 mins after doors) it is not engaging with the lock; or the part of the flap which locates in the lock is damaged/broken. The hinge lock and flap are flimsy and tricky to setup so they work but Volvo designed this to break if not locked shut so as not to cause injury. It's a tough world and made tougher by we safety conscious mortals!