VOLVO
CEM-U001000 - Medium Speed CAN Communication Bus. General Failure Information. No sub type information
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–)
Show models by year and engine (4)
What does this fault code mean?
The code concerns the medium speed CAN (MS-CAN). It is generic and does not say which type of fault lies behind it. It is set when a module gets no reply, and the gauges, instrument lighting and remote control can then stop working. The module switches itself off until its power supply is cut.
Possible causes
- Short circuit or open circuit on a CAN wire in the medium speed network
- Internal fault in the module
- Internal fault in another module on the same part of the network
What you can do
- 1Read the fault codes from all control modules and see which ones have lost communication on the medium speed network
- 2Check the network connectors for loose connections, corrosion and moisture
- 3Gently flex the wiring with the ignition on and see whether the gauges or the remote control change
- 4With a diagnostic tool, clear the fault codes and run a short test. If the fault returns straight away, it is active
- 5Resistance measurements on the network are best made by a workshop, since the network must be separated
- 6An internal module fault means the module must be replaced, which the workshop decides after fault tracing
Symptoms you may notice3
- No gauges work
- The instrument lighting does not work
- The remote control does not work
What the fault can affect2
- The module switches itself off (bus-off) and stays off until its power supply is cut
- At the next power-up the module makes new attempts to communicate
General guidance for car owners. Diagnosis on the car can point to a different cause.