DTC: P0031

Search Bulletins/Recalls for P0031

Trouble diagnosis name: Front heated oxygen sensor heater control circuit low (Bank 1)

Component Description

The heated oxygen sensor 1 is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 1 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

DTC detecting condition:

• The current amperage in the heated oxygen sensor 1 heater circuit is out of the normal range. (An excessively low voltage signal is sent to ECM through the heated oxygen sensor 1 heater.)

Possible cause:

• Harness or connectors (The heated oxygen sensor 1 heater circuit is open or shorted.)

• Front Heater oxygen sensor heater (Bank 1) may be faulty