VOLVO
CEM-5F3B - Water pump. Signal too low
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 central electronic module (CEM) has registered a low or absent signal from the water pump circuit. The cause may be poor contact, an open circuit or earth fault in the wiring, or a defective pump. If the voltage wire is faulty, codes for the fan and fuel pump may also be set, and the fault shows when the heater is active.
Possible causes
- Contact resistance in the control unit or pump connector
- Signal wire short-circuited to ground
- Open circuit in the voltage or signal wire
- Defective water pump
What you can do
- 1Read and note the code, clear it and activate the water pump to listen for a buzzing sound
- 2Check the connectors at the pump and the control unit for loose connections and corrosion, and remedy if needed
- 3If the pump works again after the connectors are repaired, the fault was probably poor contact
- 4Use a multimeter to check that the wires to the water pump have no break and no contact with ground (the body)
- 5If the wiring is intact and the fault remains, a workshop should replace the water pump
Symptoms you may notice2
- Parking heater does not work
- Poor heating in the passenger compartment
General guidance for car owners. Diagnosis on the car can point to a different cause.