HO2S Inspection Procedures
Using the Engine Signal Monitor1. Warm up the engine to normal operating temperature.
2. Connect the Special Service Tools (Engine Signal Monitor) to the PCM.
3. Measure the PCM terminal 3C and 3D voltages.
4. If not as specified, inspect the following:
- Harness and connector between heated oxygen sensor and PCM.
- On-board diagnostic system.
- Intake manifold vacuum.
- Fuel line pressure.
5. If all the systems are OK, replace the heated oxygen sensor.
Using Special Service Tools (NGS)
1. Connect the New Generation Star (NGS) tester to the data link connector 2.
2. Select the PID/DATA MONITOR AND RECORD function of the NGS.
3. Select "FHO2S", "RHO2S" on the NGS display. The NGS measures and shows the voltage.
4. If not as specified, inspect the following:
- Harness and connector between heated oxygen sensor and PCM.
- On-board diagnostic system.
- Intake manifold vacuum.
- Fuel line pressure.
5. If all the systems are OK, replace the heated oxygen sensor.
Heater Testing
1. Disconnect the heated oxygen sensor connector.
2. Measure the resistance between heated oxygen sensor terminals D and C by using an ohmmeter.
Specification: Approx. 13 ohms @ 2O°C (68°F)