Control Circuit Inspection

Ignition "OFF".
Disconnect HO2S connector.
Ignition "ON" & Engine "OFF".
Measure voltage between Heater Control terminal of the HO2S harness connector and chassis ground.
Specification: Approx. 4~5V

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

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

Go to Component Inspection procedure.

NO

Repair 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.