VOLVO
CEM-DE64 - Communication with the phone module (PHM). 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 phone module (PHM), so the phone functions and Volvo On Call do not work fully. The cause is most often supply, earth or a connector at the PHM. A break in the LS-CAN wiring can also give the same fault.
Possible causes
- No supply to the phone module (PHM)
- Open circuit in the earth wire to the PHM
- Contact resistance in the connections
- Open circuit in the LS-CAN wires to the PHM
- The PHM does not suit the car, for example a used module with other software or hardware
What you can do
- 1Switch on the infotainment system and press the phone button. If no request for a phone number appears on the display, the PHM probably has no supply or earth
- 2Check the infotainment fuse in the engine bay fuse box and the PHM fuse in the CEM. If one has blown, check its circuit for a short to earth
- 3Use a multimeter to check that the wire between the fuse and the PHM has no break and that the earth wire to the earth point is intact
- 4Check the PHM connector for contact resistance, oxidation and damage
- 5With a diagnostic tool, read the PHM ID. If it reads, the communication is probably fine and the fault may be intermittent and harder to find
- 6After the repair, clear the fault code and check that the phone function works
Symptoms you may notice1
- No or reduced Volvo On Call function
General guidance for car owners. Diagnosis on the car can point to a different cause.