VOLVO
CEM-DF17 - CAN-L, high 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?
A short between CAN L and CAN H on the high speed network gives CEM faulty signals. The engine may then not start, or it may stall. The fault most often lies in the harness.
Possible causes
- Joined CAN L and CAN H wires on the high speed network, for example through rubbed insulation
What you can do
- 1Make sure the battery is charged. A weak battery can cause several faults at once and is the easiest thing to rule out
- 2Note when the engine stalls or will not start. This shows whether the fault comes and goes or is there all the time
- 3Use a multimeter to check that the CAN L wire and the CAN H wire have no contact with each other
- 4With a diagnostic tool, read the fault codes from all control modules. The fault can show as communication faults in several of them
- 5Check the high speed network connectors for loose connections and corrosion
- 6If the measurements do not show where the fault is, have a workshop check the harness, and do not replace the CEM without a confirmed fault
Symptoms you may notice4
- The engine fails to start
- The engine stalls
- The malfunction indicator lamp is lit
- A message appears in the text display
General guidance for car owners. Diagnosis on the car can point to a different cause.