VOLVO
CEM-5F46 - Glow plug. 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 central electronic module (CEM) monitors the glow plug in the heater. If the signal circuit is short-circuited to ground or voltage, or has an open circuit, the control unit treats this as a fault and sets the code. The fault shows when the heater is active and appears as poor interior heating.
Possible causes
- Contact resistance in the control unit connector
- Open circuit in the signal wire
- Signal wire short-circuited to ground or voltage
- Contact resistance at the glow plug connection
- Damaged glow plug
What you can do
- 1Check that the heater starts and runs with only the ignition on, and that a buzzing sound can be heard
- 2Check the connectors at the glow plug and the control unit for loose connections, corrosion and damage
- 3If the heater works after the connectors are repaired, the fault was probably poor contact
- 4Use a multimeter to check that the glow plug signal wire has no break and no contact with ground (the body) or voltage
- 5If the wire is intact and the fault remains, a workshop should replace the glow plug
Symptoms you may notice1
- Poor interior heating
General guidance for car owners. Diagnosis on the car can point to a different cause.