Heated Oxygen Sensor (HO2S) Heater On-Vehicle Inspection

Disconnect sensor connector.
Using ohmmeter, measure resistance of sensor heater between terminals "VB" and "GND" at sensor connector.
If found faulty, replace HO2S.

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

HO2S heater resistance

5.0 - 6.4 Ω at 20 °C (68 °F)

Fig 1: Identifying HO2S Heater
Courtesy of SUZUKI OF AMERICA CORP.
Connect sensor connector securely.