VOLVO
AEM-5F10 - Relay, engine block heater. Signal too low. Permanent fault
System
Accessory Electronic Module (AEM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
The signal to the electric engine block heater relay is too low, and the fault persists. The relay is switched off, so the block heater does not work, and cabin heating can become poorer. The fault is most often a short to ground in the signal wire or a faulty relay.
Possible causes
- Signal wire to the engine block heater relay shorted to ground
- Faulty engine block heater relay
What you can do
- 1Look for chafing or damage on the signal wire to the relay
- 2Check the relay connector for oxidation and loose connections
- 3If the wire is intact, have a workshop replace the relay
Symptoms you may notice1
- Poor heating in the passenger compartment
What the fault can affect1
- The engine block heater relay is switched off until the ignition is next switched on
General guidance for car owners. Diagnosis on the car can point to a different cause.