VOLVO
CEM-5F13 - Relay, auxiliary heater. Signal too low. Intermittent 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 (10)
- Volvo S60 (2001–2009)2001
- 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
- Volvo S80 (1999–2006)2003–2004All engines except: B5254T2
- Volvo V70 (2000–2008)2000–2003
- Volvo V70 (2000–2008)2004All engines except: B5254T4
- Volvo V70 XC / XC70 (2001–2007)2001–2004
- Volvo XC90 (2003–)2003–2004
What does this fault code mean?
The auxiliary heater relay must not be activated for this code to be set. If the module detects a fault to ground or a break in the wire, the fault is registered. It is intermittent, so it may have occurred earlier without being active now, and it causes poor interior heating.
Possible causes
- Relay circuit short-circuited to ground or open circuit in the wire
What you can do
- 1Clear the code and road test with the auxiliary heater switched on to see whether the fault returns
- 2Check that the relay is firmly seated in its holder and is not damaged or corroded
- 3Check the auxiliary heater fuse and replace it if it has blown
- 4Use a multimeter to check that the relay wire has no break and no contact with ground (the body)
- 5Remedy what is found and check that the cabin heating improves
Symptoms you may notice1
- Poor interior heating
General guidance for car owners. Diagnosis on the car can point to a different cause.