VOLVO
CEM-DF07 - CAN-L, low speed network. Faulty signal
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 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CEM finds two wires joined together on the low speed network, and the signals become faulty. Communication between the control modules is disturbed, and the gauges, instrument lighting and remote control may stop working. On these cars the fault most often lies in the wiring between the two CAN lines.
Possible causes
- Joined wires on the low speed network, so that CAN L and CAN H touch
What you can do
- 1With the ignition on, check which functions work. If the gauges and remote control are both lost at the same time, the fault is probably in the network
- 2Check the harness for chafing, pinch damage and moisture, especially where the CAN wires lie close together
- 3With a diagnostic tool, read the fault codes from all control modules and see which ones show communication faults
- 4Use a multimeter to check that CAN L and CAN H have no connection to each other
- 5Check the connectors in the network for loose connections and corrosion
- 6Do not replace the CEM for this code until the wiring has been checked
Symptoms you may notice3
- No gauges work
- The instrument lighting does not work
- The remote control cannot be used
General guidance for car owners. Diagnosis on the car can point to a different cause.