VOLVO
CEM-B10B300 - ECM Challenge Fault. General Failure Information. No sub type information
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?
At ignition, the engine control module (ECM) should ask the central electronic module (CEM) for the immobiliser code and compare the answer with its own. The fault shows that the CEM has not received a request from the ECM within the expected time, so engine start is not permitted.
Possible causes
- The signal from the engine control module (ECM) is missing or incorrect
What you can do
- 1Read off and note the code, clear it and check whether it returns when you try to start
- 2Check that the battery is in good condition, since low voltage can disturb communication between the modules
- 3If you have a diagnostic tool, check for network or communication codes and deal with those first
- 4If the fault remains, have a workshop check the engine control module and the communication between the modules
Symptoms you may notice3
- The engine does not start
- The engine does not start or does not turn over
- No clicking sound when trying to start
What the fault can affect1
- Engine start is not permitted
General guidance for car owners. Diagnosis on the car can point to a different cause.