VOLVO
CEM-B110C77 - Rear door driver side power child 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 power child lock in the driver side rear door has its own lock motor. When the function is on, the inner door handles are disengaged and the power windows in the rear doors are disabled. The CEM follows the lock motor position through a switch in the lock unit. The code is stored when the lock motor has not reached its locked or unlocked position after two attempts, so the child lock does not work.
Possible causes
- Damaged switch that shows 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)
- 2Turn the child lock on with the driver door switch. Then the rear door should not open from inside, and the rear windows should not respond
- 3Check that the relevant fuses are intact, especially the fuse for the left rear door module in the rear relay and fuse box
- 4If the fuse has blown, use a multimeter to check the wire is not shorted to ground before replacing the fuse
- 5Look for mechanical obstructions that could block the lock motor, and check that the lock moves freely
- 6If the fault returns, have a workshop check the wiring and replace the lock unit if needed
Symptoms you may notice1
- Child lock in the driver side rear door does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.