VOLVO
CEM-B110A77 - Rear door driver side central 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:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The central electronic module (CEM) keeps track of locking and unlocking of the doors and reads the lock motor positions from switches in the lock units. The code is stored when the central locking motor in the driver side rear door has not reached its locked or unlocked position after two attempts. That rear door then does not lock with the central locking.
Possible causes
- Damaged switch that indicates the lock motor position
- The lock motor is stuck
What you can do
- 1If you have a diagnostic tool: read the fault codes in the driver and passenger door modules (DDM and PDM). Rear door faults also show in the front modules
- 2Try locking and unlocking a few times and see whether this door responds. Pause between rounds, as repeated locking heats the motors
- 3Check that the rear door lock moves freely and is not stiff
- 4Look for chafing and loose connectors on the wiring to this lock. The door trim must come off, so leave that to a workshop
- 5If the fault returns, have a workshop with diagnostic equipment check the wiring and replace the lock unit if needed
Symptoms you may notice2
- Driver side rear door does not lock or unlock with the central locking
- Central locking does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.