VOLVO
CEM-DE49 - Communication with the steering wheel module (SWM). Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CEM has lost contact with the steering wheel module (SWM), so functions controlled from the steering wheel do not work properly. This covers cruise control, the indicators, the steering wheel buttons and the wipers, which may only run at the lowest speed. The fault lies in communication on the low speed network.
Possible causes
- No supply to the steering wheel module (SWM)
- Open circuit in the earth wire to the steering wheel module
- Contact resistance in the connections
- Open circuit in the LS-CAN wires to the steering wheel module
- The steering wheel module does not suit the car, for example a used module with other software or hardware
What you can do
- 1With the ignition on, operate the indicator stalk. The indicators should flash. If they do not, the supply or communication to the steering wheel module is probably faulty
- 2Check that the steering wheel module fuses in the engine bay fuse box and in the CEM are intact
- 3Use a multimeter to check that the supply wire from the CEM to the steering wheel module has no break and is not shorted to earth
- 4Check the earth point of the steering wheel module for loose contact or oxidation
- 5With a diagnostic tool, read the steering wheel module ID. If it reads, the communication is probably fine. Press the wheel buttons and watch for changes in live data
- 6Do not replace the CEM before the communication fault with the steering wheel module has been checked
Symptoms you may notice4
- Cruise control does not work at all
- The wipers only run at the lowest speed
- The turn signals do not work
- The buttons on the steering wheel do not work
General guidance for car owners. Diagnosis on the car can point to a different cause.