VOLVO
CEM-B102481 - Start control unit. Bus Signal / Message Failures. Invalid serial data received
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) checks communication with the ignition lock control unit (SCU) and the ignition lock antenna unit (IAU). The fault code is stored when the serial communication from one of them is incorrect, and starting can then be affected.
Possible causes
- Incorrect communication from the ignition lock control unit (SCU)
- Incorrect communication from the ignition lock antenna unit (IAU)
What you can do
- 1Check that the connectors and wiring to the starter lock and the antenna unit are secure and not corroded
- 2Check that the fuses are intact
- 3The code can mean a unit was programmed for another car, which only a workshop can fix, so have one checked and replaced if needed
- 4Clear the fault code only after the workshop has dealt with the fault, then road test to confirm that starting works
Symptoms you may notice4
- The starter motor does not turn over
- A message appears in the information display
- The engine does not start, and starting may be unreliable, at times or all the time
- The immobiliser warning light does not show the correct status
General guidance for car owners. Diagnosis on the car can point to a different cause.