VOLVO
CEM-1A40 - 50-power supply. Activated too long
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 has registered that the start position (key position III) has been active for a long time, and the fault code is set. The cause is that the signal wire from the ignition switch is short-circuited to battery voltage, or that the ignition switch is faulty.
Possible causes
- Signal wire from the ignition switch short-circuited to battery voltage
- Ignition switch defective
What you can do
- 1Check with a multimeter that the start wire from the ignition switch has no battery voltage when the key is released
- 2If you have a diagnostic tool, read the code after the key is released and note whether it returns
- 3Clear the code only after the cause has been fixed
- 4If the fault remains, have a workshop replace the ignition switch
Symptoms you may notice1
- The starter motor continues to turn slowly after the ignition key has been released
General guidance for car owners. Diagnosis on the car can point to a different cause.