VOLVO
CEM-U021400 - Lost Communication With Keyless vehicle module. General Failure Information. No sub type information
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:
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 lost, or has disturbed, its communication with the keyless vehicle module (KVM). Locking with the remote and the keyless function may then fail. Tire pressure warning can also be affected. The fault concerns the communication in the network.
Possible causes
- Supply voltage to the keyless vehicle module (KVM) is missing
- Break in the KVM ground lead
- Contact resistance 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
- 1Look for the KVM fuse in the rear relay and fuse centre and confirm it is intact
- 2Check the power wire to the KVM for breaks and shorts to ground, and the ground wire for breaks
- 3Check the body ground connection for contact resistance and oxidation
- 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
- Remote control cannot lock or unlock the car
- Keyless function does not work or is reduced
- Tire pressure warning with no function
General guidance for car owners. Diagnosis on the car can point to a different cause.