VOLVO
CEM-B1C5519 - Horn Relay. General Electrical Failures. Circuit current above threshold
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 controls the horn relay. The fault is stored when the current in the relay drive circuit is too high, which is caused by the drive circuit being short-circuited to voltage. It is detected when the horn is activated.
Possible causes
- The relay drive circuit is short-circuited to voltage
What you can do
- 1Check that the fuse for the horn is intact
- 2Press the horn to see whether it sounds, then clear the fault code and road test
- 3Check the wire from the CEM to the horn relay for chafing and pinch damage
- 4Use a multimeter to check that the wire is not short-circuited to battery voltage with the connectors disconnected
- 5If the fault returns, have a workshop with diagnostic equipment check the relay and the CEM
Symptoms you may notice1
- The horn does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.