DTC ECM-990A

Condition







Diagnostic trouble code (DTC) ECM-990A is stored if the engine control module (ECM) registers that the nominal idle speed (engine coolant temperature (ECT) above 60 degrees C) deviates, either in being 200 rpm over or 100 rpm below the nominal idle speed.

Substitute value
- None.

Possible source

Faulty signal:
- Search the air and fuel supplies in the fuel system for the fault cause (air leakage, blockages etc).

Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- High idling speed
- Low idling speed.