VOLVO
CEM-1C06 - Alternator control module (ACM). Electrical fault
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (16)
- Volvo S60 (2001–2009)2005All engines except: B5244S6
- Volvo S60 (2001–2009)2006All engines except: B5244S6, D5244T4, D5244T5, D5244T6, D5244T7
- Volvo S60 (2001–2009)2007–2009All engines except: D5244T4, D5244T5, D5244T7
- Volvo S80 (1999–2006)2005–2006
- Volvo V70 (2000–2008)2005All engines except: D5244T3
- Volvo V70 (2000–2008)2006All engines except: D5244T4, D5244T5, D5244T6, D5244T7
- Volvo V70 (2000–2008)2007All engines except: D5244T4, D5244T5, D5244T7
- Volvo V70 (2000–2008)2008All engines except: D5244T5, D5244T7
- Volvo V70 XC / XC70 (2001–2007)2005
- Volvo V70 XC / XC70 (2001–2007)2006All engines except: D5244T4
- Volvo V70 XC / XC70 (2001–2007)2007Engine B5254T2 only
- Volvo XC90 (2003–)2005All engines except: B8444S
- Volvo XC90 (2003–)2006All engines except: B8444S, D5244T4
- Volvo XC90 (2003–)2007–2012Engine B5254T2 only
- Volvo XC90 (2003–)2013–2014Engine B5254T9 only
- Volvo XC90 (2003–)2015
What does this fault code mean?
The CEM has received a message from the generator's control module (ACM) about an electrical fault in the generator. The cause may be worn brushes, a damaged charge regulator or a damaged generator. The battery may discharge and the starter motor may turn slowly.
Possible causes
- A battery charger with too high charging voltage was connected earlier
- Worn carbon brushes
- A damaged generator control module (charge regulator)
- A damaged generator
What you can do
- 1Check that the battery terminals and ground connection are clean and tight. Poor connections can cause faulty charging
- 2Check that the generator drive belt is intact and tensioned. Replace a worn belt
- 3Think back: was a battery charger connected earlier? It may have damaged the charge regulator
- 4If you have a diagnostic tool, follow the battery voltage in live data with the engine running and check that it stays steady when large loads are switched on
- 5After the work, clear the code and check that the charging warning does not light again. The fault may be intermittent
Symptoms you may notice4
- The charging lamp lights while the engine is running
- The battery discharges
- The starter motor turns slowly
- The battery electrolyte may boil with the engine running
General guidance for car owners. Diagnosis on the car can point to a different cause.