VOLVO
CEM-DD10 - Communication with the light switch module (LSM). Signal missing
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 central module receives no signal from the light switch module (LSM), even though communication should run over the signal wire. The cause may be a short circuit or break in the signal wires, or a fault in another control module on the network. The light switch and the beam height control are affected.
Possible causes
- Short circuit between the signal wires
- Open circuit in one of the signal wires
- Fault in another control module on the same network
What you can do
- 1Check that the wiring to the light switch is not chafed or broken
- 2With a multimeter, check that the signal wire has no contact with ground (the car body)
- 3Check that the connectors in the wiring are secure and clean
- 4If the wire is intact, have a workshop replace the light switch and check its function
Symptoms you may notice2
- The light switch does not work
- The beam height control does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.