System Inspection

Heated Oxygen Sensor Heater (Front)
Using SST-Engine Signal Monitor.
1. Remove the ECM.




2. Connect the SSTs to the ECM.
3. Turn the ignition switch to ON.
4. Measure the voltage at ECM terminal 4E and 4I by using a voltmeter.

Specification: Below 1.0 V

5. Position the vehicle on a chassis roller and shift the selector lever to D.




6. Increase the engine speed over 4,000 rpm and measure the voltage at ECM terminals 4E and 4I by using a volt meter.

Specification: Battery positive voltage

7. If not as specified, inspect following:
- ECM terminal 3E voltage (Mass air flow sensor)
- ECM terminal 4AL, 4AH voltage (Crankshaft position sensor)
- Heated oxygen sensor

Heated Oxygen Sensor Heater (Rear)
1. Remove the ECM.
2. Connect the SSTs to the ECM.
3. Start the engine.
4. Measure the ECM terminal 2F voltage by using a voltmeter.

Specification: Below 1.0 V

5. Position the vehicle on a chassis roller and shift the selector lever to D.
6. Increase the vehicle speed over 80 km/h (50 mile/h) and measure the voltage at ECM terminal 2F.

Specification: Battery positive voltage

7. If not as specified, inspect following:
- ECM terminal 1C voltage (Vehicle speed sensor)
- Heated oxygen sensor heater relay



Inspection Using SST-New Generation Star Tester (NGS)

NOTE: SST-(NGS) will only test the operation of the FRONT Heated Oxygen Sensor Heater circuit.




1. Connect the SST to the data link connector-2.




2. Select the PID/DATA MONITOR AND RECORD function of the NGS.
3. Select "HO2SHR" and "HO2SHL" on the NGS display.
4. Verify that the NGS display shows "ON".
5. Start the engine.
6. Increase the engine speed over 4,000 rpm and verify that the NGS display turns to "OFF".
7. If not as specified, inspect following:
- ECM terminal 3E voltage (Mass air flow sensor)
- ECM terminal 4AL, 4AH voltage (Crankshaft position sensor)
Heated oxygen sensor