VOLVO
CEM-8F61 - Relay, heated rear windshield. Faulty signal
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CEM has registered too low a signal on the driver circuit for the rear defroster relay. The electric heating of the rear window then does not work, because the relay is not being driven correctly.
Possible causes
- Short to ground
- Open circuit in the signal wire
What you can do
- 1Test the rear window defroster with the ignition on: if it does not start the fault is permanent, and if it starts the fault has occurred before
- 2Check that the rear defroster relay is seated properly
- 3With the ignition off, use a multimeter to check that the signal wire has no break
- 4Use a multimeter to check that the signal wire has no contact with ground (the body)
- 5If the fault returns, have a workshop check the wire and the relay
Symptoms you may notice1
- The rear window heating does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.