Heated Oxygen Sensor (Ho2S): Testing: Voltmeter

NOTE: Warm up the engine up to the extent that the engine coolant temperature reaches 80-95°C (176-203°F) prior to start the check.

Directly apply the battery voltage between terminal 4 and 3.
NOTE: Be sure to correctly apply the voltage since any incorrect connection or a short circuit may destroy the system.
Use a digital voltmeter to connect between terminal 2 and 1.
Measure the oxygen sensor output voltage during running the engine continuously.

Fig 1: Sensor Output Voltage Chart
Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: Measuring Sensor Output Voltage
Courtesy of KIA MOTORS AMERICA, INC.
If there is any abnormality, it may be caused from the oxygen sensor.
Tightening torque

Heated oxygen sensor: 28.9-36.2 lb-ft

(400~500 kg-cm)