Heated Oxygen Sensor (HO2S) Inspection

HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZR 2.5]

HO2S 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)
- O2S12 (HO2S output voltage)

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 HO2S output voltage (PID: O2S12) is 0.3 V or less while decelerating as shown in the figure.






- If not as specified, replace the HO2S. Heated Oxygen Sensor (HO2S) Removal/Installation

HO2S Heater Inspection

1. Remove the battery cover. Removal and Replacement

2. Disconnect the negative battery cable. Removal and Replacement

3. Disconnect the HO2S connector.

4. Measure the resistance between HO2S terminals C and D.






- If not as specified, replace the HO2S. Heated Oxygen Sensor (HO2S) Removal/Installation

HO2S heater resistance
- 2-50 ohms [normal temperature]