VOLVO
CEM-U020800 - Lost Communication With Power seat 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 no working link to the power seat module (PSM), or the link is disturbed. Automatic adjustment of the seat and outer mirrors may then stop working. The fault concerns the network rather than one individual control module.
Possible causes
- No voltage feed to the power seat module (PSM)
- Broken ground wire to the PSM
- 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
- 1Try adjusting the seat by hand to see whether the seat motors work at all, and compare with the automatic function
- 2Confirm the fuse for the PSM in the rear relay and fuse centre is intact
- 3Check the supply wire between the centre and the PSM for breaks and shorts to ground
- 4Check the ground wire for breaks, contact resistance and oxidation. If the fault returns, have a workshop check the CAN wiring
Symptoms you may notice1
- Automatic adjustment of the power seat and outer mirrors does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.