VOLVO
CEM-6C44 - Antenna/light ring wire data communication (IDS). Signal too low. Intermittent fault
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:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The data communication wire between the CEM and the antenna unit around the ignition switch gives too low a signal. The cause may be a break in the +15 supply to the ignition switch, a break in the data communication or an earth fault. The fault is intermittent, so it may have occurred earlier without being active now.
Possible causes
- Open circuit in the +15 supply
- Open circuit in the data communication wire
- Earth fault in the data communication wire
What you can do
- 1With the ignition off, check the earth lead of the antenna unit for loose connections and corrosion
- 2With the ignition on, check that the supply to the ignition switch is present, for example by checking the fuse
- 3Check the signal wire for chafing and loose connections, and check the connectors at the CEM and the antenna unit for corrosion
- 4Use a multimeter to check that the data communication wire has no break and no contact with ground (the body), testing one wire at a time
- 5If the fault returns and the wires are intact, a workshop should investigate the antenna unit
Symptoms you may notice2
- Engine will not start
- Starter motor does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.