VOLVO
CEM-U018100 - Lost Communication With Headlamp Leveling Control Module. General Failure Information. No sub type information
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The fault code means that the control module storing the fault has no working link to the headlamp control module (HCM), or the link is disturbed. The HCM drives the headlamps, so low beam and high beam may fail to work when the link breaks. The fault concerns communication and not one individual control module.
Possible causes
- No voltage supply to the headlamp control module (HCM)
- Broken ground wire to the HCM
- Poor contact in the connections
- Open or shorted CAN wiring
- A module not intended for the car, such as a used unit with other software or hardware
What you can do
- 1Check that the fuse for the headlamp control module in the engine bay relay and fuse centre is intact
- 2Check the power wire for breaks and shorts to ground, and the connector for contact resistance, oxidation and looseness
- 3Check the ground wire for breaks or a short to voltage, and the ground point on the body
- 4If the fault returns, have a workshop check the CAN wiring. Replace the CEM only if testing shows it is damaged
Symptoms you may notice3
- Low beam does not work
- High beam flash does not work
- High beam does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.