VOLVO
CEM-B108B24 - Start Button Circuit A. General Signal Failures. Signal stuck high
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The central electronic module (CEM) monitors the two switches in the start button, where the second sends its signal over the LIN bus. The fault shows that the first switch stayed active over an extended period while the start button closes the second, which suggests the signal from the first switch is too high. The fault is checked when the start button is pressed.
Possible causes
- The signal wire is shorted to ground
- Damaged switch
- Internal fault in the ignition lock control module (SCU)
What you can do
- 1Check that the start button is not stuck in position and returns fully when released
- 2Check that the fuses are intact
- 3Check that the connectors at the start button are fully engaged and that the cable is not pinched
- 4If you have a diagnostic tool, press the start button and check in live data that the first switch returns to off when the button is released
- 5Use a multimeter (ignition off, connector unplugged) to check that the signal wire has no connection to ground
- 6If the fault remains, have a workshop check the start button and the ignition lock control module
Symptoms you may notice1
- The steering lock does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.