Oxygen Sensor: Testing and Inspection

Fig. 41 Check Connector Test Harness:

1. Check oxygen sensor as follows:
a. Raise engine temperature to operating temperature.
b. Disconnect oxygen sensor and connect a volt/ohmmeter to oxygen sensor terminals.
c. Raise engine speed. Ensure volt/ohmmeter reads .45 volts or more.
d. If reading is less than .45 volts, replace oxygen sensor.
2. Inspect oxygen system as follows:
a. Connect check connector test harness.
b. With engine at operating temperature, connect brown terminal to black terminal on check connector test harness.
c. Hold engine speed at 3000 RPM for two minutes.
d. Measure voltage between green terminal and body ground, Fig. 41.
e. If voltage does not change eight times or more in ten seconds and no diagnosis codes are present, replace oxygen sensor.
3. Perform Oxygen Sensor circuit test.

Fig. 68 ECU System Diagnosis, Oxygen Sensor Check: