P04BB: Fuel Fill Door Lock Control Circuit Open

What it means

Fuel Fill Door Lock Control Circuit Open: the control circuit is open. Likely a broken wire, disconnected connector, or failed actuator.

How it works

The fuel-fill door lock actuator uses a control circuit to lock or release the door, while the control module monitors whether that circuit can carry the commanded operation. P04BB sets when the lock-control circuit is open, so current cannot follow its intended path. A broken wire, disconnected connector, or failed actuator winding can cause the open circuit.

Common causes

Most likely first.

1. Open in harness or actuator winding
2. Pin pushed back out of connector body
3. Cracked solder joint inside the module or sensor

Symptoms

• Fuel-fill door may not lock
• Fuel-fill door warning or status may be incorrect

How to diagnose it

1. Check live fuel-door lock status and stored data to confirm which lock command failed.
2. Inspect the actuator connector and harness for a disconnected plug, broken wire, or pushed-back pin.
3. Check the lock actuator and linkage for visible damage that could have pulled or damaged the wiring.
4. Measure continuity through the control circuit and actuator winding using the manufacturer's specification.
5. If the circuit is intact to the module, check the module-side connection and its output as specified by the manufacturer.

Common fixes

• Reconnect the actuator plug or secure a loose terminal.
• Repair a broken control wire or pushed-back connector pin.
• Replace a failed lock actuator if its winding is open.
• Repair a confirmed failed circuit connection inside a module only after wiring and actuator tests.

Can I keep driving?

Driving is generally safe, but the fuel-fill door may not lock and its status may be unreliable. Check that the door is closed and secure before driving, especially if it can open while moving.