mazda Workshop Repair Guides

Mazda Workshop Service and Repair Manuals

Engine Controls/Emissions - OBD II Diagnosis Aid|Page 1929 > < Engine Controls/Emissions - OBD II Diagnosis Aid|Page 1927
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Oxygen Sensor: Testing and Inspection

Inspection of voltage

1. Warm up the engine to normal operating temperature and stop it.
2. Disconnect the heated oxygen sensor connector.
3. Connect a voltmeter to the heated oxygen sensor.
4. Start the engine and increase engine speed to 2000 rpm.
5. Check that the voltage changes between 0.2-1 .0 V when accelerating and decelerating.

Inspection of heater

1. Disconnect the heated oxygen sensor connector.
2. Measure the resistance between the heater terminals.

Resistance: 2-5 Ohms @ 20°C (68°F)
Hot to warm resistance: 5-30 Ohms

3. If not as specified, replace the heated oxygen sensor(s).

Engine Controls/Emissions - OBD II Diagnosis Aid|Page 1929 > < Engine Controls/Emissions - OBD II Diagnosis Aid|Page 1927