Diagnostic trouble code (DTC) information ECM-2A0A

Condition

Fig 1: Identifying Rear Heated Oxygen Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The engine control module (ECM) checks that there are no faults in the probe or the wiring. Diagnostic trouble code (DTC) ECM-2A0A is stored if the control module registers that the signal deviates from the permitted operating range.

Substitute Value

twin 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
Defective heated oxygen sensor (HO2S).

Signal too low:

Short-circuit to ground in the signal cable
Short-circuit to ground in the ground lead
Defective 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
Defective 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
Defective heated oxygen sensor (HO2S).

Fault symptom[s]

Malfunction indicator lamp (MIL) lit.