VOLVO
ECM-2224 - Auxiliary heater relay. Signal faulty. Intermittent fault
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS40 (1996–2004), V40 (1996–2004)
Show models by year and engine (2)
What does this fault code mean?
The fault is intermittent, meaning it comes and goes, and it concerns the wire feeding the auxiliary heater relay. The code is also set if the engine control module finds that the power draw does not change when the auxiliary heater is switched on or off. The fault can lie in the wire, the relay or the heater element, and the auxiliary heater is then switched off.
Possible causes
- Signal wire short-circuited to voltage
- Open circuit in the signal wire
- Signal wire short-circuited to ground
- Defective auxiliary heater relay
- Defective auxiliary heater element
What you can do
- 1Have a diagnostic tool? Activate the auxiliary heater and check that it starts
- 2Inspect the wire between the relay and the heater element for breaks, chafing and loose clips
- 3Check the connectors at the relay and the heater element for play and oxidation
- 4Use a multimeter to check that the wire to the relay is not broken or shorted to ground or voltage
- 5If the wiring is sound but the fault returns, have a workshop check the relay and the heater element
Symptoms you may notice1
- No noticeable symptoms for the driver
What the fault can affect1
- The auxiliary heater is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.