Heated Oxygen Sensor (HO2S) Heater On-Vehicle Inspection

Heated Oxygen Sensor (HO2S) Heater On-Vehicle Inspection

1. Disconnect sensor connector.
2. Using ohmmeter, measure resistance of sensor heater between terminals "VB" and "GND" at sensor connector.

If found faulty, replace oxygen sensor.

NOTE: Temperature of sensor affects resistance value largely. Make sure that sensor heater is at correct temperature.

Viewed From Terminal Side:

HO2S heater resistance
5.0 - 6.4 ohms at 20 °C (68 °F)

3. Connect sensor connector securely.