VOLVO
CEM-B11DB83 - Battery Monitoring Module. Bus Signal / Message Failures. Value of signal protection calculation incorrect
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The CEM keeps watch on the battery monitoring sensor (BMS) across a shared LIN bus. The message from the sensor carries a checksum that does not match when the fault is stored, and The causes are an open circuit in the LIN connection between the CEM and the sensor, or a damaged sensor.
Possible causes
- Open circuit in the LIN connection between the CEM and the battery monitoring sensor
- Damaged battery monitoring sensor
What you can do
- 1Check that the fuses are intact
- 2Check the wire from the battery monitoring sensor to the battery positive for breaks and short circuits to earth
- 3Check the signal wire between the sensor and the CEM for intermittent short circuits to earth, breaks, and oxidised or loose connectors
- 4Clear the fault code and check whether it returns after the engine has been started
- 5If no fault is found on the wiring to the CEM, have a workshop check the battery monitoring sensor, which will probably need replacing
Symptoms you may notice2
- The automatic start/stop function does not work while driving
- The automatic start/stop function does not work at idle
General guidance for car owners. Diagnosis on the car can point to a different cause.