Oxygen Sensor: Testing and Inspection

CIRCUIT DIAGRAM





USING SCAN TOOL











HARNESS INSPECTION PROCEDURES

SENSOR INSPECTION
1. Disconnect the heated oxygen sensor connector, and connect the special tool (harness connector) to the heated oxygen sensor side.





2. Check that there is continuity [approx. 12 Ohms at 20°C (68°F)] between heated oxygen sensor connector terminal (3) (red clip of special tool) and terminal (4) (blue clip).
3. If there is no continuity, replace the heated oxygen sensor.
4. Warm up the engine until the engine coolant temperature exceeds 80°C (176°F).
5. Use jumper wires to connect heated oxygen sensor terminal (3) (red clip of special tool) and terminal (4) (blue clip) to the battery (+) terminal and (-) terminal.

CAUTION: Be very careful when connecting the jumper wires because the heated oxygen sensor will be damaged if a mistake is made in the connecting terminals.





6. Connect a digital Voltmeter between terminal (1) (yellow clip of special tool) and terminal (2) (black clip).





7. While repeatedly racing the engine, measure the output Voltage of the heated oxygen sensor.