Signal Circuit Inspection

Check for Open or Short in signal circuit
1. IG KEY "OFF".
2. Disconnect HO2S (S1) connector.
3. IG KEY "ON" & ENG "OFF"
4. Measure the voltage between signal terminal of HO2S (S1) harness connector and chassis ground.
  Specification: Approx 0.45V
  
  Fig 1: Measuring Voltage Between Signal Terminal Of HO2S (S1) Harness Connector & Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
5. Is the measured voltage within specification?
  YES
  - Go to "GROUND CIRCUIT INSPECTION " procedure.
  NO
  - Repair Open or Short circuit, and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.