Volvo s60 2003 fuel door lock

[Jokerz]

Ive noticed that the door lock mechanism doesnt lock the fuel door. If a slide it form the inside of the trunk to closed position it unlocks, but doesnt lock it shut.
Has anyone experienced this? Is there a simple cure like cleaning or something or i must change the mechanism?

[RickHaleParker]

From the 2003 S60 owners manual.

"Fuel filler door
The fuel filler door, located on the right rear fender, is connected to your car's central locking system.
Press the button on the light switch panel (see illustration on page 30) when the car is at a standstill to unlock the fuel filler door. Please note that the fuel filler door will remain unlocked until the car begins to move forward. An audible click will be heard when the fuel filler door relocks."

[darylrobert]

Theres a delay on locking, its like 10minutes if it doesnt lock then start checking the wiring, relay , voltages etc.

When i repaired mine

Step 1 check voltage at solenoid=no voltage

Step 2 remove solenoid and check using 12volts still no movement.

Step 3 take solenoid apart and check, found bad design connection to motor. Got it working.

Step 4 track wiring for continuity back to the relay, good connection but found relay was missing.

Step 5 unlocking works but not locking, wait 10minutes and its locked.

[oragex]

You'll need a set of tiny torx bits, the screws are pretty tight.

[mrbrian200]

According to the wiring diagram the fuel door lock motor is driven through a closed loop to the REM (momentary reversing polarity 12v DC voltage to lock or unlock). However- one side of this circuit is tied through a wire junction that goes to the right rear door lock motor. So it appears as though the fuel door will lock/unlock controlled by the REM when you start driving or push the unlock button on the dash. What the tie in to the right rear door lock motor does I cannot determine. As my own testing showed that the fuel door does neither locks or unlocks with the doors on mine.

This is a simple DC motor driving a sliding pin, if it's not working and you've determined there isn't a wiring problem I would find a used one. You should be able to test it by unplugging the electrical connector and powering the lock motor directly with a 9v battery or the like.

A misconception with these is that it's a spring loaded solenoid latch like would expected on most other makes/models. Which is not the case. It's a slide pin driven by a DC motor through a simple gear mechanism. When locked the pin slides through the little loop on the fuel door. To unlock the REM reverses polarity to the DC motor to retract the pin. Momentary power is applied for about 1 second, the pin moves and stays in position.

[Jokerz]

Thanks guys!
I dissasembled the unit, checked the motor with a multimeter, there was no resistance so i found a replacement motor from a RC car witch operated on 12V.
Cleaned the unit and lubed it with industrial lubricant, and now it works!
The unit was simpler than i thought.