Heated Oxygen Sensor (HO2S) Inspection
HEATED OXYGEN SENSOR (HO2S) INSPECTION [13B-MSP]
HO2S voltage 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)
- HO2S voltage (PID: O2S12)
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 outputs a voltage of 0.6 V or more, one time or more, then verify that the HO2S voltage (PID: O2S12) is 0.3 V or less while decelerating as shown in the figure.
- If not within the specification, inspect the HO2S for an open or short circuit. Then if there is no malfunction in the wiring harness, replace the HO2S. Heated Oxygen Sensor (HO2S) Removal/Installation
HO2S circuit open/short inspection
1. Disconnect the PCM connector.
2. Disconnect the HO2S connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)
Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- HO2S terminal A and PCM terminal 2Q
- HO2S terminal B and PCM terminal 2BH
Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- HO2S terminal A and body ground
- HO2S terminal A and power supply
- HO2S terminal B and power supply
HO2S heater resistance inspection
1. Disconnect the HO2S connector.
2. Measure the HO2S resistance between terminals C and D.
- If not within the specification, replace the HO2S. Heated Oxygen Sensor (HO2S) Removal/Installation
HO2S heater resistance
- 2-50 ohms
HO2S circuit open/short inspection (heater)
1. Disconnect the PCM connector.
2. Disconnect the HO2S connector.
3. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)
Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- HO2S terminal C and main relay terminal C
- HO2S terminal D and PCM terminal 2BE
Short circuit
- If there is no continuity, there is a short circuit. Repair or replace the wiring harness.
- HO2S terminal C and body ground
- HO2S terminal D and power supply
- HO2S terminal D and body ground