FRONT HEATED OXYGEN SENSOR (HO2S) INSPECTION[ZJ, ZY, Z6]

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Note

•  Before performing the following inspection, make sure to follow the procedure as indicated in the troubleshooting flowchart. (See HOW TO USE THIS MANUAL.)

Front Heated Oxygen Sensor (HO2S) Voltage Inspection (Without Throttle Valve Actuator)

1.  Warm UP the engine to normal operating temperature.

2.  Using the M-MDS, monitor the following:

―  Vehicle speed (PID: VSS)

―  Engine speed (PID: RPM)

―  Front HO2S voltage (PID: O2S11)

3.  Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more.

4.  Verify that the front HO2S outputs a voltage of 0.6 V or more, one time or more, then verify that the front HO2S voltage (PID: O2S11) is 0.3 V is or less while decelerating as shown in the figure.

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•  If not within the specification, inspect the front HO2S for an open or short circuit. (See Front Heated Oxygen Sensor (HO2S) Current Inspection (With Throttle Valve Actuator).) Then if there is nomalfunction in the wiring harness, replace the front HO2S. (See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

Front Heated Oxygen Sensor (HO2S) Current Inspection (With Throttle Valve Actuator)

1.  Warm up the engine to normal operating temperature.

2.  Using the M-MDS, monitor the following:

•  Vehicle speed (PID: VSS)

•  Engine speed (PID: RPM)

•  Front HO2S current (PID: O2S11)

3.  Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more.

4.  Verify that the front HO2S current (PID: O2S11) is 0.25 mA or more while decelerating as shown in the figure.

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•  If not within the specification, inspect the front HO2S for an open or short circuit. (See Short circuit.) Then if there is no malfunction in the wiring harness, replace the front HO2S.

Front Heated Oxygen Sensor (HO2S) Circuit Open/Short Inspection (Without Throttle Valve Actuator)

1.  Remove the PCM connector cover.

2.  Disconnect the PCM connector. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

3.  Inspect the following wiring harness for open or short circuit (continuity check).

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Open circuit

•  If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

―  Front HO2S terminal A and PCM terminal 2AI

―  Front HO2S terminal B and PCM terminal 2AX

Short circuit

•  If there is continuity, there is a short circuit. Repair or replace the wiring harness.

―  Front HO2S terminal A and power supply

―  Front HO2S terminal A and body ground

―  Front HO2S terminal B and power supply

―  Front HO2S terminal B and body ground

Front Heated Oxygen Sensor (HO2S) Circuit Open/Short Inspection (With Throttle Valve Actuator)

1.  Remove the PCM connector cover.

2.  Disconnect the PCM connector. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

3.  Disconnect the front HO2S connector.

4.  Inspect the following wiring harness for open or short circuit (Continuity inspection).

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Open circuit

•  If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

―  Front HO2S terminal A and PCM terminal 2Z

―  Front HO2S terminal B and PCM terminal 2AD

Short circuit

•  If there is continuity, there is a short circuit. Repair or replace the wiring harness.

―  Front HO2S terminal A and power supply

―  Front HO2S terminal A and body ground

―  Front HO2S terminal B and power supply

―  Front HO2S terminal B and body ground

Front Heated Oxygen Sensor (HO2S) Heater Resistance Inspection (Without Throttle Valve Actuator)

1.  Disconnect the front HO2S connector.

2.  Measure the resistance between front HO2S terminals C and D.

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•  If not within the specification, replace the front HO2S. (See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

•  If the monitor item condition/specification (reference) is not within the specification, even though there is no malfunction, perform the “Circuit Open/Short Inspection”.

Front Heated Oxygen Sensor (HO2S) Heater Resistance Inspection (With Throttle Valve Actuator)

1.  Disconnect the front HO2S connector.

2.  Measure the resistance between front HO2S terminals C and D.

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•  If not within the specification, replace the front HO2S. (See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

•  If the monitor item condition/specification (reference) is not within the specification, even though there is no malfunction, perform the "Circuit Open/Short Inspection".

Front Heated Oxygen Sensor (HO2S) Heater Circuit Open/Short Inspection (Without Throttle Valve Actuator)

1.  Remove the PCM connector cover.

2.  Disconnect the PCM connector. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

3.  Inspect the following wiring harness for open or short circuit (continuity check).

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Open circuit

•  If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

―  Front HO2S terminal C and PCM terminal 2T

―  Front HO2S terminal D and PCM terminal 2AM

Short circuit

•  If there is continuity, there is a short circuit. Repair or replace the wiring harness.

―  Front HO2S terminal C and body ground

―  Front HO2S terminal D and power supply

―  Front HO2S terminal D and body ground

Front Heated Oxygen Sensor (HO2S) Heater Circuit Open/Short Inspection (With Throttle Valve Actuator)

1.  Remove the PCM connector cover.

2.  Disconnect the PCM connector. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION[ZJ, ZY, Z6].)

3.  Inspect the following wiring harness for open or short circuit (Continuity inspection).

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Open circuit

•  If there is no continuity, there is an open circuit. Repair or replace the wiring harness.

―  Front HO2S terminal C and PCM terminal 2I

―  Front HO2S terminal D and PCM terminal 2X

Short circuit

•  If there is continuity, there is a short circuit. Repair or replace the wiring harness.

―  Front HO2S terminal C and body ground

―  Front HO2S terminal D and power supply

―  Front HO2S terminal D and body ground