VOLVO
CEM-B10AD87 - Rain sensor. 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 both sends and receives information over the LIN bus and communicates with the rain sensor. The fault shows that no communication arrives from the rain sensor at all, so the automatic windscreen wiping does not work.
Possible causes
- Contact resistance, oxidation or a loose connection in connectors and joints
- Damaged rain sensor
What you can do
- 1Read off and note the code and check whether it returns when the ignition is switched on
- 2Check that the connector to the rain sensor is fully engaged and not corroded
- 3Check that the fuses for the windscreen wipers are intact
- 4Use a multimeter (ignition off, connector unplugged) to check that the wires to the rain sensor have no break and no contact with ground or battery positive
- 5If the fault remains, have a workshop check the rain sensor and the wiring
Symptoms you may notice1
- The automatic windscreen wipers do not work
General guidance for car owners. Diagnosis on the car can point to a different cause.