VOLVO
CEM-1A08 - 50-Power supply. Signal missing. 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 CEM has registered an open circuit, or a short to ground, in the 50-supply, and the fault is intermittent. It was present at an earlier time but is no longer there. The starter motor may therefore work at some times.
Possible causes
- Contact resistance in the terminals
- Open circuit or short to ground in the 50-supply
- Starter relay not active
- Defective ignition switch
What you can do
- 1Check that the connectors at the CEM and the ignition switch are secure and free from corrosion
- 2Lightly move the wiring at the connectors and see whether the fault returns
- 3Check with a multimeter that the wire has no contact with ground (the bodywork) when the connector is disconnected
- 4If the fault returns, have a workshop check the starter relay and replace the ignition switch
Symptoms you may notice1
- The starter motor does not turn
General guidance for car owners. Diagnosis on the car can point to a different cause.