Control Circuit Inspection

Ignition "OFF".
Disconnect HO2S sensor connector.
Ignition "ON"&Eng. "OFF".
Measure voltage between control terminal of the HO2S heater harness connector and chassis ground.
Specification: Approx. 4~5V

Fig 1: Measuring Voltage Between Control Terminal Of HO2S Heater Connector And Chassis Ground (1 Of 2)
Courtesy of HYUNDAI MOTOR CO.

Fig 2: Measuring Voltage Between Control Terminal Of HO2S Heater Connector And Chassis Ground (2 Of 2)
Courtesy of HYUNDAI MOTOR CO.
Is voltage within the specification?
YES

Go to next step as below.

NO

Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

NOTE: HO2S must have a clean air reference to function properly. The air is obtained by way of the sensor wire (s). Do not attempt to repair the wire (s), connector, or the terminals.