VOLVO
CEM-U016400 - Lost Communication With Climate control unit. 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 link to the climate control module (CCM). The climate system may then behave wrongly: it can be fully off, or keep running even after the key is removed. The fault concerns the network.
Possible causes
- No power supply to the climate control module (CCM)
- Broken ground wire to the module
- 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
- 1Switch the ignition on and the cabin blower on. The fan should blow and its speed should be adjustable
- 2Check that the climate system fuse in the engine bay central fuse box is intact
- 3Check the CCM ground wire and ground point for breaks, play 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
- Climate control does not work at all
- Climate control keeps working after the key is removed
- Function button does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.