VOLVO
CEM-5F42 - Power supply. Faulty
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 (10)
- Volvo S60 (2001–2009)2001, 2005–2009
- Volvo S60 (2001–2009)2002All engines except: D5244T2
- Volvo S60 (2001–2009)2003All engines except: B5244S6, D5244T2
- Volvo S60 (2001–2009)2004All engines except: B5244S6, B5254T4, D5244T2
- Volvo S80 (1999–2006)1999–2002, 2005–2006
- Volvo S80 (1999–2006)2003–2004All engines except: B5254T2
- Volvo V70 (2000–2008)2000–2003, 2005–2008
- Volvo V70 (2000–2008)2004All engines except: B5254T4
- Volvo V70 XC / XC70 (2001–2007)2001–2007
- Volvo XC90 (2003–)2003–2015
What does this fault code mean?
The shared feed for the fuel pump, water pump and fan has been short-circuited to voltage supply, and the central electronic module (CEM) sets the code. The fault shows when the heater is active and stops the heater from working properly, which appears as poor heating in the passenger compartment.
Possible causes
- Power supply wire short-circuited to voltage supply
What you can do
- 1Read and note the code, clear it and check that the heater runs after the repair
- 2Check the power supply wire to the heater for chafing, pinching and loose connections
- 3Use a multimeter to check that the power supply wire to the heater has no contact with voltage supply, and remedy the fault
- 4Have a workshop remove the heater to access the connectors and check them
- 5Test-run the heater after the repair and check that the cabin heating improves
Symptoms you may notice1
- Poor heating in the passenger compartment
General guidance for car owners. Diagnosis on the car can point to a different cause.