VOLVO
CEM-U000900 - High Speed CAN Communication Bus (-) shorted to 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:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
On the V40 the wires of the high speed CAN are shorted to each other, which disturbs communication between the control modules. The engine may then have trouble starting, and driving and the gauges are affected. The fault most often lies in the harness where the wires run close together.
Possible causes
- The wires of the high speed CAN have come into contact with each other
What you can do
- 1Check that the harness is not chafed or pinched where the CAN wires lie close together
- 2Check the high speed network connectors for loose connections, corrosion and moisture
- 3With a diagnostic tool, read the fault codes from all control modules and start with those for the CAN network
- 4Use a multimeter to check that the two CAN wires have no connection with each other
- 5Gently flex the harness with the ignition on and see whether the fault code changes
- 6If the engine stalls while driving, avoid long journeys and have a workshop trace the fault promptly
Symptoms you may notice4
- The engine does not start even though the starter turns
- Poor performance and lack of power at start
- The throttle response hesitates, surges or is jerky
- Cruise control cannot be engaged
General guidance for car owners. Diagnosis on the car can point to a different cause.