VOLVO
CEM-B10ED77 - Rear door driver side 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 controls locking and unlocking of the door lock motors. For the rear door on the driver side, the CEM gets the lock motor position through the driver door module (DDM). The code is stored when no confirmation arrives that the lock motor for the blocked lock position has reached the requested position. The rear door then does not lock, or does not unlock, as it should.
Possible causes
- Lost signal exchange with the driver door module (DDM)
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 check they are empty before going further
- 2Try locking and unlocking a few times with the remote control, pausing between rounds because repeated locking heats the motors
- 3Activate the deadlock and see whether the rear door on the driver side locks like the other doors. If not, the fault is most likely in the door lock or its wiring
- 4Look for chafing and loose connectors in the wiring between the driver door module and the lock. The door trim has to come off for this, so have a workshop do it
- 5If the fault returns, have a workshop with diagnostic equipment check the module and update its software or replace the lock
Symptoms you may notice1
- Driver side rear 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.