Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-2A0A

Condition




The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

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

Possible source

Signal too high
- Short-circuit to supply voltage in the signal cable
- Short-circuit to supply voltage in the ground lead
- Damaged rear heated oxygen sensor (HO2S).

Signal too low
- Short-circuit to ground in the signal cable
- Short-circuit to ground in the ground lead
- Damaged rear heated oxygen sensor (HO2S).

Faulty signal
- Short-circuit in the signal cable for the pre-heating circuit
- Short-circuit in the ground lead for the preheating circuit
- Damaged rear heated oxygen sensor (HO2S).

Signal missing
- Contact resistance or oxidation in the connectors
- Open-circuit in the signal cable
- Open-circuit in the ground lead
- Damaged rear heated oxygen sensor (HO2S).

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