VOLVO
CEM-8F42 - Relay, tailgate wiper motor. Faulty signal
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsC70 (2006–2013), V50 (2004–2013)
Show models by year and engine (2)
What does this fault code mean?
Although the code is named faulty signal, it means the CEM has an internal fault. The rear wiper motor then does not work, and because the same relay also controls the windscreen wipers and the front washer, they can be affected too.
Possible causes
- Fault inside the control module
What you can do
- 1Clear the code and check whether it returns with the ignition on
- 2Check that the windscreen wipers and the front washing work, since the same relay controls them
- 3Check whether the rear wiper runs; if it runs now, the fault occurred earlier and is intermittent
- 4If you have a diagnostic tool, read the customer parameters and see whether anything is out of line
- 5If the fault returns, have a workshop replace the central electronic module (CEM)
Symptoms you may notice3
- The rear wiper motor does not work
- Front windscreen washing does not work
- The windscreen wipers do not work
General guidance for car owners. Diagnosis on the car can point to a different cause.