VOLVO
CEM-B112A12 - Relay B 15-feed. General Electrical Failures. Circuit short to battery
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The CEM controls a distribution relay for the 15 feed, which is switched on when the ignition is turned on. On cars built before mid-November 2009, the relay is in the rear fuse box in the luggage compartment. On later cars it sits in the fuse box in the cabin, next to the CEM. The code is stored when the output to the relay coil is short-circuited to supply voltage.
Possible causes
- The cable is short-circuited to supply voltage
What you can do
- 1Check that the relevant fuses are intact. Their locations are in the owner's manual or on the fuse box cover
- 2The relay is in the luggage compartment fuse box on cars built before mid-November 2009, and in the cabin on later cars
- 3Use a multimeter to check whether the relay wire has voltage when the ignition is off
- 4Look for chafing and pinch damage on the cable to the relay
- 5If you have a diagnostic tool: activate the all-wheel drive or the active chassis and check whether the function responds
- 6If the fault returns, have a workshop with diagnostic equipment check the relay and the wiring
Symptoms you may notice3
- All-wheel drive does not work
- Four-C function does not work
- Active chassis does not work
What the fault can affect3
- The function switches off in the driving cycle in which the fault is detected
- Permanent shut-off follows after 100 driving cycles with the fault
- Clearing the fault codes and starting a new driving cycle resets the output
General guidance for car owners. Diagnosis on the car can point to a different cause.