VOLVO
CEM-DF01 - CAN-H, low speed network. Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
10 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), S60 (2001–2009), S80 (1999–2006), V50 (2004–2013), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (10)
- Volvo C30 (2007–2013)2007–2013
- Volvo C30 Electric (2011–2013)2011–2013
- Volvo C70 (2006–2013)2006–2013
- Volvo S40 (2004–2013)2004–2012
- Volvo S60 (2001–2009)2005–2009
- Volvo S80 (1999–2006)2005–2006
- Volvo V50 (2004–2013)2004–2012
- Volvo V70 (2000–2008)2005–2008
- Volvo V70 XC / XC70 (2001–2007)2005–2007
- Volvo XC90 (2003–)2005–2015
What does this fault code mean?
The CEM detects an open circuit in the CAN H wire on the low speed network, so communication between several control modules may be lost. The gauges, instrument lighting and central locking can then stop working. The fault should be traced in the network wiring, not by replacing the CEM.
Possible causes
- Open circuit in the CAN H wire on the low speed network, for example a chafed or pinched cable
- Contact resistance or oxidation in a connector on the CAN network
- Open circuit in another of the CAN wires on the low speed network
What you can do
- 1Read the fault codes from every control module you can reach. Communication faults in several modules at once often point to a shared fault in the network
- 2With a diagnostic tool, check whether the code can be read from more than one module. If it can, the fault is probably intermittent
- 3Gently flex the cable harness and tug the connectors while watching the communication. If the fault changes, that shows where it sits
- 4Use a multimeter to check that the CAN H wire is continuous along its whole length and not broken
- 5Check that the harness is not chafed or pinched, especially where it moves or passes through a grommet
- 6The CEM should not be replaced for a CAN fault unless a workshop has confirmed an internal CEM fault
Symptoms you may notice3
- No gauges work
- The instrument panel lighting does not work
- The central locking does not work at all
General guidance for car owners. Diagnosis on the car can point to a different cause.