VOLVO
CEM-B1C8413 - Heated Rear Window Relay Output. General Electrical Failures. Circuit open
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The central electronic module (CEM) controls the rear window heater and has registered an open circuit in the signal wire to it. With the wire broken the rear window cannot be defogged.
Possible causes
- Open circuit on the signal wire to the rear window heater
What you can do
- 1Read and clear the code, then switch on the rear window defroster and see whether it works
- 2Check the rear window heater fuse in the passenger compartment fuse box
- 3Look for loose, corroded or broken connectors on the signal wire to the rear window heater
- 4Use a multimeter to check that the signal wire is continuous between its two ends
- 5If the wire is intact, have a workshop with diagnostic equipment check the module output and the rear window heater
Symptoms you may notice1
- Defogging of the rear window does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.