Front Heated Oxygen Sensor (HO2S) Inspection
FRONT HEATED OXYGEN SENSOR (HO2S) INSPECTIONNOTE: Before performing the following inspection, make sure to follow the troubleshooting flowchart. (See FOREWORD.) Foreword
Front HO2S Current Inspection
1. Warm up the engine to normal operating temperature.
2. Using the M-MDS, verify that the current of the front HO2S (M-MDS PID: 02S11) is as indicated in the table.
Front HO2S Current:
- If it cannot be verified even though the related harnesses have no malfunction, replace the front HO2S.
Front HO2S Heater Resistance Inspection
1. Disconnect the front H02S connector.
2. Measure the resistance between front HO2S terminals C and D.
- If not within the specification, replace the front HO2S.
Front HO2S heater resistance
2.16 - 2.90 ohms [20 °C {68 °F}]
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Disconnect the front HO2S connector.
3. Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)
Open circuit
- If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.
- Front HO2S terminal A and PCM terminal 2B
- Front HO2S terminal B and PCM terminal 2C
- Front HO2S terminal C and main relay terminal C
- Front HO2S terminal D and PCM terminal 1 V
Short circuit
- If there is continuity in the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.
- Front HO2S terminal A and body ground
- Front HO2S terminal A and power supply
- Front HO2S terminal B and body ground
- Front HO2S terminal B and power supply
- Front HO2S terminal D and body ground