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: 4-5 V

Fig 1: Measuring Voltage Between Heater Control Terminal Of HO2S Harness Connector And Chassis Ground
Courtesy of HYUNDAI MOTOR CO.
Is voltage within the specification?
YES
- Go to COMPONENT INSPECTION .
NO
- Repair as necessary and go to VERIFICATION OF VEHICLE REPAIR .
  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.