Air Fuel Ratio (A/F) Sensor Inspection

AIR FUEL RATIO (A/F) SENSOR INSPECTION [MZR 2.5]

A/F Sensor Inspection

1. Warm up the engine to normal operating temperature.

2. Access the following PIDs using the M-MDS: On-Board Diagnostic Test

- VSS (Vehicle speed)
- RPM (Engine speed)
- O2S11 (A/F sensor output current)

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 within the specification, replace the A/F sensor. Air Fuel Ratio (A/F) Sensor Removal/Installation

A/F Sensor Heater Inspection

1. Disconnect the negative battery cable. Removal and Replacement

2. Disconnect the A/F sensor connector.

3. Measure the resistance between A/F sensor terminals A and E.






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

A/F sensor heater resistance
- 1-10 ohms