VOLVO
CEM-8F31 - Relay, headlamp wash / wipe. Signal too high
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
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 monitors the headlamp washer motor and has registered too high a signal on the driver circuit for the headlamp washer relay. The washer motor then cannot be switched off.
Possible causes
- Short to supply voltage
What you can do
- 1With the ignition on, activate the headlamp washer and listen for the relay click: no click means a permanent fault, a working washer means an earlier fault
- 2Check that the headlamp washer relay is seated correctly in place
- 3Look for spots where the cable to the relay may have touched voltage, such as chafing or pinch damage
- 4With the ignition off, use a multimeter to check that the cable to the relay has no contact with voltage
- 5If the fault returns, have a workshop check the cable and replace the relay if needed
Symptoms you may notice1
- The washer motor cannot be switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.