VOLVO
CEM-B12E811 - Liftgate/Tailgate Control/Release Switch. General Electrical Failures. Circuit short to ground
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?
The tailgate opening switch is connected directly to the CEM. The fault is stored when the switch is constantly activated for too long, and the cause is either a switch that has stuck or a signal wire that is short-circuited to earth.
Possible causes
- The tailgate opening switch has stuck in the activated position
- The signal wire is short-circuited to earth
What you can do
- 1Check that the fuses are intact
- 2Press the tailgate opening button a few times and check that it returns to its resting position
- 3If you have a diagnostic tool, check in live data that the tailgate opening switch reads off when it is not pressed
- 4With the connectors disconnected, use a multimeter to check that the signal wire has no contact with earth (the body)
- 5If the fault returns, have a workshop with diagnostic equipment check the CEM and the tailgate wiring
Symptoms you may notice1
- It is difficult to open the tailgate
General guidance for car owners. Diagnosis on the car can point to a different cause.