VOLVO
CEM-6F84 - Fuel Flap Driver Faulty Signal
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
CEM controls the power supply to the fuel filler cap lock motor through a directly connected wire. If the wire to the motor is short-circuited to voltage or ground, or has an open circuit, the fault code is set. The fuel filler cap then cannot be unlocked, or is hard to open.
Possible causes
- Power supply wire to the fuel filler lock motor short-circuited to ground
- Power supply wire to the fuel filler lock motor short-circuited to voltage or open circuit
What you can do
- 1With the ignition off, check the wire to the fuel filler lock motor for chafing, pinching and loose connections
- 2Use a multimeter to check that the supply wire has no break and no contact with ground (the body) or voltage
- 3Check the connectors at the CEM and at the fuel filler lock motor for damage and corrosion
- 4If no other fault is found, a workshop should replace the fuel filler lock motor
- 5Clear the fault code and check that the fuel filler cap unlocks when the button is pressed
Symptoms you may notice2
- Fuel filler cap does not lock or unlock
- Fuel filler cap is hard or impossible to open
General guidance for car owners. Diagnosis on the car can point to a different cause.