VOLVO
ECM-4421 - Engine control module. 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 engine control module (ECM) has registered an internal fault in itself. The fault is intermittent, meaning it occurred on an earlier occasion, but when the module checked again it was no longer present. The code is stored in the engine control module.
Possible causes
- Signal fault inside the engine control module
- Defective engine control module
What you can do
- 1Read off and note the fault code, erase it and test-drive to see whether it returns
- 2Check that the fuses for engine management are intact and that the battery is in good charge
- 3If the fault returns or the engine will not start, have a workshop check the engine control module, since the fault lies inside it
Symptoms you may notice1
- The engine does not start
General guidance for car owners. Diagnosis on the car can point to a different cause.