Heated Oxygen Sensor: Inspection: Procedure

INSPECT HEATED OXYGEN SENSOR

PID/DATA Monitor Inspection (HO2S)

Connect the techstream to the DLC-2.
Start the engine and warm it up completely.
Access the following PIDs using the techstream.
Refer to ON-BOARD DIAGNOSTIC TEST
- VSS (Vehicle speed)
- RPM (Engine speed)
- O2S12 (HO2S output voltage)
Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3, 000 rpm or more.

Verify that the HO2S output voltage (PID: O2S12) changes as shown in the figure during deceleration. (outputs 0.6 V or more once or more, then 0.3 V or less.)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	VSS
*b	RPM
*c	O2S12
*d	0.3 V or Less

If not as verified, replace the HO2S.

Refer to REMOVAL

Resistance Inspection (HO2S Heater)

WARNING:

A hot engine and exhaust system can cause severe burns. Turn off the engine and wait until they are cool before removing the exhaust system.

NOTE:

Do not allow flammable objects such as the taping for bundling wiring harness to come into contact with the exhaust manifold and silencer.

Disconnect the negative battery cable.
Refer to REMOVAL
Lift up the vehicle.
Remove the insulator.
Refer to REMOVAL
Disconnect the HO2S connector.

Measure the resistance between HO2S terminals 1 and 3.

If not as specified, replace the HO2S.

Refer to REMOVAL

HO2S heater resistance

2 to 50 ohms