Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-25B0

Condition




The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the heated oxygen sensor (HO2S) indicates an incorrect lean or rich fuel/air mixture compared to that anticipated by the engine control module (ECM).

Note! The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute value
- The heated oxygen sensor (HO2S) control is disabled
- Three-way catalytic converter (TWC) diagnostics are disabled.

Possible source
- Leakage in the exhaust system
- Short-circuit to supply voltage or ground in signal cable (-)
- Short-circuit to supply voltage or ground in the pump supply cable
- Short-circuit to supply voltage or ground in calibration supply cable
- Open-circuit in signal cable (+)
- Damaged heated oxygen sensor (HO2S).

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