VOLVO
CEM-5B09 - Communication with the seat heater module. Signal missing. Intermittent fault
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The central electronic module (CEM) cannot establish communication with the left seat heater control module. The fault is intermittent, so it may have occurred earlier without being active now. The cause may be a defective control module in the seat, although connectors can also affect the communication.
Possible causes
- Defective seat heater control module in the left-hand seat
What you can do
- 1Clear the code and road test with the seat heater switched on to see whether the fault returns
- 2Check the connectors to the seat heater control module for loose connections and corrosion
- 3Check that the fuse for the seat heater is intact
- 4If you have a diagnostic tool, look for the seat heater control module and check that it responds
- 5If the control module has an internal fault it must be replaced, which a workshop should do
Symptoms you may notice1
- Front left seat heating does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.