VOLVO
CEM-B100B88 - External receiver. Bus Signal / Message Failures. Bus off
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 central electronic module (CEM) communicates with the remote receiver (RRX) when the ignition is switched on. The fault code is stored when that communication is incorrect, here because the LIN bus is shorted to voltage or earth. Tyre pressure monitoring may then show faults and the remote control may stop working.
Possible causes
- LIN bus shorted to voltage or earth
- Internal fault in the remote receiver (RRX)
What you can do
- 1Check that the wiring to the remote receiver has no chafing or pinching, especially where the cable passes through the body
- 2With the ignition off, use a multimeter to check whether the LIN wire has contact with earth (the body) or voltage
- 3Check that the connectors are secure and dry
- 4Clear the fault code and road test to see whether it returns
- 5If the fault remains, have a workshop isolate the bus and find the faulty part with diagnostic equipment
Symptoms you may notice2
- Tyre pressure monitoring warning lights and chimes do not show the correct status
- The remote control does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.