VOLVO
CEM-U002812 - Extended CAN Communication Bus. General Electrical Failures. Circuit short to battery
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS60 (2011–), V60 (2011–), V60 Cross Country (2015–), XC60 (2009–)
Show models by year and engine (4)
What does this fault code mean?
The fault code means that one of the wires in the extended CAN network has contact with voltage. The extended network is the part where the control modules for the park assist camera, blind spot system and rear cross traffic alert talk to the rest of the car. Voltage on a CAN wire disturbs the signals, so the systems on that network may not work until the fault is gone.
Possible causes
- Chafed or pinched wiring lets one extended-network wire touch a live wire
What you can do
- 1Read and note the fault codes in all control modules, clear them and road test the car to see whether the code returns
- 2Switch the ignition off and inspect the wiring for chafing, pinch damage and connectors that are loose or corroded
- 3Use a multimeter to confirm the extended-network wires have no contact with voltage. Wiggle harness and connectors during the test
- 4If the code returns, have a workshop with diagnostic equipment measure the voltage drop on the CAN wires. Replace the CEM only if testing shows it is faulty
Symptoms you may notice3
- Park assist camera does not work
- Blind spot monitoring (BLIS) does not function
- Cross Traffic Alert (CTA) does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.