VOLVO
CEM-B108C23 - Start Button Circuit B. General Signal Failures. Signal stuck low
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 second switch does not close at the same time as the first when the start button is pressed, so the signal is read as low. The fault is checked when the start button is pressed.
Possible causes
- Damaged switch
- Internal fault in the ignition lock control module (SCU)
What you can do
- 1Check that the start button returns fully when released and is not stuck
- 2Check that the fuses are intact
- 3Check that the connectors at the start button are fully engaged and not corroded
- 4If you have a diagnostic tool, press the start button and follow the switch status in live data; both should change to on
- 5Use a multimeter (ignition off, connector unplugged) to check that the start button wires have no breaks
- 6If the fault remains, have a workshop check the start button and the ignition lock control module
Symptoms you may notice2
- The steering lock does not lock or unlock
- The steering lock does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.