VOLVO
CEM-8F2D - Wipers. Signal too low. Intermittent fault
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 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The fault is intermittent: on an earlier occasion the CEM registered that the wiper stayed somewhere on the glass too long, while the steering wheel module (SWM) had not asked for it to run. It is no longer present, but the cause may be a signal wire shorted to ground, or a damaged wiper motor.
Possible causes
- Signal wire between the CEM and the rain sensor shorted to ground
- Signal wire from the wiper motor position sensor to the CEM shorted to ground
- Damaged windscreen wiper motor
- Signal wire to the rain sensor may be pinched under the base of the interior mirror
What you can do
- 1Clear the code and check whether it returns; an intermittent fault can be a temporary disturbance
- 2Check that the wipers have not stuck on the glass
- 3Look for an intermittent short to ground in the signal wires to the rain sensor and the wiper motor position sensor
- 4Check that the connectors are firmly seated and clean
- 5If the fault returns, have a workshop check the wiring and replace the wiper motor if needed
Symptoms you may notice2
- The wiper motor does not work, and the wiper may have stuck on the glass
- The rain sensor does not work
What the fault can affect2
- The wipers run at low speed for a while and then stop anywhere on the glass
- After several repeats the wipers stand still for a while before the cycle starts again
General guidance for car owners. Diagnosis on the car can point to a different cause.