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Air Fuel Ratio (A/F) Sensor Inspection





AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 1.5]

A/F Sensor Inspection

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)
- A/F sensor 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 A/F sensor current (PID: O2S11) is 0.25 mA or more while decelerating as shown in the figure.






- If not as specified, replace the A/F sensor. Air Fuel Ratio (A/F) Sensor Removal/Installation

A/F Sensor Heater Inspection

1. Disconnect the A/F sensor connector.

2. Measure the resistance between A/F sensor terminals C and D.






- If not as specified, replace the A/F sensor. Air Fuel Ratio (A/F) Sensor Removal/Installation

A/F sensor heater resistance
- 1-10 ohms