VOLVO
CEM-DD12 - Communication with the left-hand gas discharge lamp module (GDL). Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
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 central module has lost contact with the left gas discharge lamp module (GDL) for a longer period. It shows in the headlamps, where low beam, high beam and high beam flash do not work. The cause may be a fault in the LIN wire, a faulty module or a fault in another unit on the same network.
Possible causes
- Short circuit between the LIN wires
- Open circuit in one of the LIN wires
- Fault in the left gas discharge lamp module
- Fault in another unit on the same LIN network
What you can do
- 1Check the headlamp fuse, and replace it if it is blown, using the owner's manual
- 2With a multimeter, check the wire between the central module and the left gas discharge lamp module for breaks and contact with ground
- 3Check that the connectors to the left gas discharge lamp module are secure and clean
- 4If the wire is intact, have a workshop replace the left gas discharge lamp module
Symptoms you may notice2
- Low beam does not work
- High beam and high beam flash do not work
General guidance for car owners. Diagnosis on the car can point to a different cause.