Heated Oxygen Sensor (HO2S-2) Heater

Heated Oxygen Sensor (HO2S-2) Heater On-Vehicle Inspection

WARNING: To avoid danger of being burned, do not touch exhaust system when system is hot. Sensor inspection should be performed when system is cool.

Heater
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.

HO2S heater resistance
5.0 - 6.4 Ohms at 20 degrees C (68 degrees F)

3. Connect sensor connector securely.

Circuit Insulation Check
1. Disconnect connector from HO2 sensor.
2. Using ohmmeter, check circuit insulation of HO2S sensor. If faulty is found, replace HO2S sensor.




- Between each heater terminal (1) and other than heater terminals (2).




- Between each terminal ((1), (2), (3) and (4)) of HO2S sensor and HO2S sensor body (5).

3. Connect HO2S sensor connector securely.