VOLVO
CEM-8FA1 - Relay, horn. Signal too high. 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: the signal to the horn relay coil was too high on an earlier occasion, but it is no longer present. It may come from a defective relay with a short in the coil, and then the horn may stop working.
Possible causes
- Defective relay with a short in the coil
What you can do
- 1Clear the code and check whether it returns; an intermittent fault can be a temporary disturbance
- 2Press the horn with the ignition on and listen for whether it sounds
- 3Check that the horn relay sits firmly in its place
- 4Look for chafing on the wire to the horn relay where it may have touched voltage
- 5If the fault returns, have a workshop check the wire for a short to voltage and replace the relay if needed
Symptoms you may notice1
- The horn does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.