Control Circuit Inspection

Ignition "OFF".
Disconnect HO2S connector.
Ignition "ON", Engine "OFF".
Measure voltage between VG terminal of the sensor harness connector and chassis ground.
Specification: Approx. 2-3V
Measure resistance between VG terminal and other terminals of the HO2S harness connector.
Specification: Infinite

Fig 1: Measuring Voltage Between VG Terminal Of Sensor Harness Connector And Chassis Ground
Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: Measuring Resistance Between VG Terminal And Other Terminals Of HO2S Harness Connector
Courtesy of KIA MOTORS AMERICA, INC.
Is HO2S display near the specification?
YES
- Go to next step.
NO
- Repair open or short to ground in signal circuit 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.