DTC P0031 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1); DTC P0032 Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1): Description

WARNING: This page is about a different car, the 2009 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.

Refer to DTC P2195 .

HINT:

When either of these DTCs is set, the ECM enters fail-safe mode. The ECM turns off the A/F sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned to OFF.
The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The A/F sensor heater circuit uses a relay on the +B side of the circuit.

Fig 1: A/F Sensor - Circuit Diagram

DTC DETECTION CONDITIONS CHART

DTC No.	DTC Detection Conditions	Trouble Areas
P0031	Air-Fuel Ratio (A/F) sensor heater current less than 0.8 A (1 trip detection logic)	Open in A/F sensor heater circuit A/F sensor heater A/F HEATER relay ECM
P0032	Air-Fuel Ratio (A/F) sensor heater current more than 10 A (1 trip detection logic)	Short in A/F sensor heater circuit A/F sensor heater A/F HEATER relay ECM