FRONT HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZI-3.7]

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Sensor Output Value Inspection (Front HO2S)

1.  Warm up the engine to normal operating temperature.

2.  Using the M-MDS, monitor the following: (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7].)

―  Vehicle speed (PID: VSS)

―  Engine speed (PID: RPM)

―  Front HO2S voltage (PID: O2S11, O2S21)

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, O2S21) is 0.3 V is or less while decelerating as shown in the figure.

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•  If not within the specification, replace the front HO2S. (See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZI-3.7].)

Resistance Inspection (Front HO2S Heater)

1.  Disconnect the front HO2S connector.

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

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•  If it is not within the specification, replace the front HO2S. (See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZI-3.7].)