Component Inspection

HEATED OXYGEN SENSOR
Inspection of Terminal Voltage
1. Warm up the engine to normal operating temperature and let it idle.
2. Disconnect the heated oxygen sensor connector.






3. Connect a voltmeter between the heated oxygen sensor terminal A and B.
4. Measure the voltage while increasing and decreasing the engine speed suddenly several times.






While Decelerating: Below 0.4 Volts
While Accelerating: Above 0.5 Volts

5. Replace the heated oxygen sensor if not as specified.


Inspection of Sensitivity
1. Warm up the engine to normal operating temperature.

View: Test Connections:

2. Connect the Special Service Tools (SSTs), (System Selector and Self-Diagnosis Checker) to the data link connector as shown.
3. Set switch A to position 1.
4. Set TEST SW to 02 MONITOR.
5. Increase the engine speed to 2,000 and 3,000 rpm.
a. Press the brake pedal to check the right sensor.
b. Release the brake pedal to check the left sensor.






Specification: The monitor lamp should flash more than eight times in ten seconds.

6. Replace the heated oxygen sensor if not as specified.






Inspection of Heater
1. Measure resistance between terminals C and B.

Resistance: 5-7 ohms 20°C (68°F)

2. Replace the heater if not as specified.