VOLVO
CEM-9A01 - Interior lighting. Signal too high
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CEM controls the interior lighting through an output and has registered too high a signal from that output. The interior lighting then does not work, because the control signal wire has come into contact with battery voltage.
Possible causes
- Signal wire to the interior lighting shorted to battery voltage
What you can do
- 1Check that the interior lighting switch is in the auto position
- 2With the ignition on, activate the interior lighting: if it does not light the fault is permanent, and if it lights the fault has occurred before
- 3With the ignition off, use a multimeter to check that the control signal wire has no contact with voltage
- 4Look for chafing on the wire where it may have touched voltage
- 5If the fault returns, have a workshop repair the wire
Symptoms you may notice1
- The interior lighting does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.