VOLVO
CEM-B10EC77 - Passenger door double locking motor. Mechanical Failures. Commanded position not reachable
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The CEM handles locking and unlocking of the door lock motors and receives the lock motor position over the CAN network from the door control modules. The code is stored when no confirmation comes back from the passenger door module that the deadlock motor has reached the correct position after locking or unlocking. The passenger door then does not lock as it should.
Possible causes
- Lost signal exchange with the passenger door module (PDM)
What you can do
- 1If you have a diagnostic tool: read the fault codes in the driver and passenger door modules (DDM and PDM) and note them
- 2Test locking a few times with the remote or the central locking button. Repeated locking heats the motors, so pause between rounds
- 3Activate the deadlock and check whether every door gives a clicking lock sound. If only the passenger door is silent, suspect its lock or wiring
- 4Look for chafing and loose connectors in the cable between the passenger door module and the lock. The door trim must come off, so have a workshop check
- 5If the fault returns, have a workshop with diagnostic equipment check the module and update its software or replace the lock motor
Symptoms you may notice1
- Passenger door will not lock or unlock when activated and deactivated
General guidance for car owners. Diagnosis on the car can point to a different cause.