VOLVO
CEM-1A11 - Secondary battery Signal too high
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (4)
What does this fault code mean?
This fault only applies to cars with automatic engine start and stop. The CEM monitors the secondary battery voltage, and the fault code is set when the voltage is too high. This can happen if a battery charger with the wrong voltage has been used.
Possible causes
- A battery charger with the wrong voltage has been used
What you can do
- 1Has a battery charger been used recently? Check that it is meant for the car's battery
- 2Check that the battery is not damaged, for example swollen or leaking
- 3Check that the battery terminals and connections are clean and tight
- 4Clear the code and road test the car to see whether it returns
- 5If the fault remains, have a workshop check the secondary battery and the charging
Symptoms you may notice2
- Automatic engine start and stop does not work
- Idling with automatic engine start and stop does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.