Heated Oxygen Sensor Heater On-Vehicle Inspection

Disconnect H02S-1 or -2 coupler.
Using ohmmeter, measure resistance between terminals "VB" and "GND" of H02S coupler (1). If found faulty, replace H02S.
NOTE: Temperature of H02S affects resistance value largely.

Make sure that H02S heater is at specified temperature.

Resistance of HO2S heater

H02S-1: 5.0 - 6.4 ohm (at 20°C (68°F))

H02S-2: 11.7 - 14.3 ohm (at 20°C (68°F))

Fig 1: Inspecting Heated Oxygen Sensor Heater
Courtesy of SUZUKI OF AMERICA CORP.
Connect H02S coupler securely.