VOLVO
CEM-B123396 - Interior Motion Sensor "B". Bus Signal / Message Failures. Component Failures
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS60 (2011–), V60 (2011–), V60 Cross Country (2015–), XC60 (2009–)
Show models by year and engine (4)
What does this fault code mean?
The interior motion sensor (MMS) checks its own function when the alarm is activated. If it finds an internal fault, it sends an error message to the CEM, which then sets the fault code. The fault is therefore in the motion sensor itself and not in the wiring.
Possible causes
- Internal fault in the motion sensor
What you can do
- 1Check that the motion sensor has a good power supply
- 2Activate the alarm and see whether the sensor triggers, then clear the fault code and road test
- 3If the code returns after the road test the fault is permanent; if it does not return the fault may have been intermittent
- 4Check that the connectors at the motion sensor are secure and not corroded
- 5If the fault is permanent, the motion sensor needs replacing, which is a job for a workshop
Symptoms you may notice2
- The alarm does not respond when the sensor should trigger it
- A message appears in the text display
General guidance for car owners. Diagnosis on the car can point to a different cause.