VOLVO
CEM-5F3E - Heater fan. Signal 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 heater fan has run too slowly according to the signal the control unit receives, and the central electronic module (CEM) treats this as a fault and sets the code. The fault shows when the heater is active and mainly appears as poorer heating in the passenger compartment.
Possible causes
- Defective or damaged heater fan
- Contact resistance in the control unit or fan connectors
What you can do
- 1Read and note the code, clear it and activate the heater fan to listen for a buzzing sound
- 2Check the connectors at the fan and the control unit for loose connections and corrosion, and remedy if needed
- 3If the fan runs normally after the connectors are repaired, the fault was probably poor contact
- 4If you have a diagnostic tool, activate the heater fan and follow its status in live data to check that it runs steadily
- 5If the fan still runs too slowly, a workshop should replace the heater fan
Symptoms you may notice1
- Poor interior heating
General guidance for car owners. Diagnosis on the car can point to a different cause.