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 & Chassis Ground
Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: Measuring Resistance Between VG Terminal & Other Terminals Of HO2S Harness Connector
Courtesy of KIA MOTORS AMERICA, INC.
Is HO2S display near the specification?
YES
- Go to next step as below
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.