DTC ECM-250A

Condition







The control module receives information from the heated oxygen sensor (HO2S) about fuel/air mixture at different loads. Diagnostic trouble code (DTC) ECM-250A is stored if the control module registers that fuel/air mixture deviates to much from target lambda, leaving the long-term trim in one of its limit positions.

Substitute value
None.

Possible source

Upper limit:
- defective mass air flow (MAF) sensor
- low fuel pressure
- air leakage

Lower limit:
- defective mass air flow (MAF) sensor
- high fuel pressure
- leaking injectors
- leaking evaporative emission (EVAP) system
- contaminated engine oil
- oil level too high

Fault symptom[s]
- may result in poor performance
- can result in high fuel consumption.