VOLVO
ECM-0100 - Air flow sensor. Faulty signal
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 has received an incorrect signal from the air flow sensor. The causes are most often contact problems, a break or short in the wiring, a blocked intake system, or a faulty sensor. The fault may be shown by the malfunction indicator lamp lighting up.
Possible causes
- Contact resistance in the connections
- Break or short circuit in the signal wire, ground wire or power supply
- Blocked intake system
- Faulty air flow sensor
What you can do
- 1Check that the air filter is not clogged
- 2With the ignition off, check the plugs at the control module and at the air flow sensor for poor contact, resistance and oxidation
- 3Use a multimeter to check that the wiring to the air flow sensor has no break and no short to ground or supply voltage
- 4If the fault returns although the wiring and connectors are sound, have a workshop replace the air flow sensor
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lights up
General guidance for car owners. Diagnosis on the car can point to a different cause.