Circuit Description

Refer to DTC P0130 OXYGEN SENSOR CIRCUIT (BANK 1 SENSOR 1), DTC P2195 OXYGEN SENSOR SIGNAL STUCK LEAN (BANK 1 SENSOR 1), DTC P2196 OXYGEN SENSOR SIGNAL STUCK RICH (BANK 1 SENSOR 1) .

HINT:

The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated oxygen sensor heater circuit uses a relay on the B+ side of the circuit.

Fig 1: Oxygen Sensor Heater Control Circuit Low Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2) Diagram

DTC

DTC No.	DTC Detection Condition	Trouble Area
P0031 P0037	Heater Current Is 0.25 A Or Less When Heater Operates With +B Greater Than 11.5 V (1 Trip Detection Logic)	Open Or Short In Heater Circuit Of Heated Oxygen Sensor Heated Oxygen Sensor Heater EFI Relay ECM
P0032 P0038	Heater Current Exceeds 2 A When The Heater Operates. (1 Trip Detection Logic)