Diagnostic Trouble Code (DTC) Information ECM-2A

Diagnostic trouble code (DTC) information ECM-2A

Condition
The engine control module (ECM) checks the activity of the signal from the rear heated oxygen sensor (HO2S). During acceleration after engine braking, the fuel-air mixture is richer. This means that the signal from the rear heated oxygen sensor (HO2S) should rise to a certain level. Diagnostic trouble code (DTC) ECM-2A is stored if the signal from the rear heated oxygen sensor (HO2S) does not rise during acceleration after engine braking or does not drop during fuel shut-off.

Substitute value
- Fuel trim disabled
- Three-way catalytic converter (TWC) diagnostic disabled.

Possible source
- Contact resistance in the terminals
- Leakage in the exhaust system
- Defective rear heated oxygen sensor (HO2S).

Fault symptom[s]
- Malfunction indicator lamp (MIL) lit.