VOLVO
CEM-B112F87 - Emergency brake lamp. Bus Signal / Message Failures. Missing message
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 monitors the link to the brake control module (BCM). The code is stored when the signal from the BCM is missing. The tail light or brake light then does not work as it should. The cause lies in the BCM.
Possible causes
- The cause lies in the brake control module (BCM)
What you can do
- 1The brake system is safety critical. Do not try to troubleshoot the brakes or the BCM yourself; have a workshop with diagnostic equipment check the fault
- 2Check that the brake lights work by having someone watch them while you press the brake
- 3If you have a diagnostic tool: read the fault codes in the brake control module (BCM) and deal with them first
- 4Check that the relevant fuses are intact. Their locations are in the owner's manual or on the fuse box cover
- 5If the fault returns, have a workshop check the communication with the BCM
Symptoms you may notice1
- Tail light or brake light does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.