Control Circuit Inspection

Check for Short in control circuit
1. IG KEY "OFF".
2. Disconnect HO2S (S2) connector.
3. IG KEY "ON" & ENG "OFF"
4. Measure the voltage between heater control terminal of HO2S (S2) harness connector and chassis ground.
  Specification: Approx. 3.5V
  
  Fig 1: Measuring Voltage Between Heater Control Terminal Of HO2S (S2) Harness Connector & Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
5. Is the measured voltage within specification?
  YES
  
  Go to "COMPONENT INSPECTION " procedure.
  
  NO
  
  Repair Open or Short in control circuit, and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.