What does it mean?
This is a performance code for the fuel filler door lock output: the circuit is electrically valid but the result is wrong. The module commands the lock, then checks either the current the actuator draws or the feedback from the lock position sensor, and what comes back does not match what a healthy locking event looks like. Typical triggers are an actuator that draws current for too long because the pin never reaches its seat, a movement that finishes far too quickly, or a lock state that never confirms within the allowed time. Unlike an open or shorted circuit fault, this one usually points to a binding mechanism, a partly failed motor or a misadjusted latch rather than to damaged wiring. The customer normally reports that the filler door sometimes locks and sometimes does not.
Symptoms
- Fuel filler door locks inconsistently, working some times and not others
- Weak, slow or laboured sound from the lock actuator
- MIL (check engine lamp) on with fuel filler door lock codes
- Door reported as unlocked in live data even after a lock command
- Complaint that appears mostly in cold or wet weather
- Repeat attempts needed before the lock finally engages
Likely causes
- Lock pin binding in a corroded or dirty latch so the actuator cannot complete its travel
- Worn actuator motor with high internal resistance producing weak, slow movement
- Ice or debris in the lock mechanism during cold or dirty conditions
- Misaligned filler door or latch, so the pin does not line up with its hole
- High resistance in the supply or ground of the actuator circuit, reducing available current
- Lock position sensor reporting late or not at all, so the module cannot confirm the event
- Low system voltage or a weak battery during the locking attempt
How to fix it
- Command the lock and unlock functions with a scan tool while watching the lock position feedback and listening to the actuator
- Measure actuator current draw during a lock event; a high sustained current points to binding and a very low one to a weak motor
- Operate the lock mechanism by hand with the actuator removed to feel for binding, corrosion or ice
- Check filler door and latch alignment, adjusting where the design allows
- Perform voltage drop tests on the supply and ground of the actuator circuit under load rather than at rest
- Clean and lubricate the mechanism, then repeat the test before replacing anything
- Replace the actuator or the lock assembly if it still performs poorly, then verify several lock and unlock cycles complete normally