Ground Circuit Inspection

Check for Open in ground circuit
1. IG KEY "OFF".
2. Disconnect HO2S (S1) connector.
3. Measure resistance between ground terminal of HO2S (S1) and chassis ground.
  Specification: below 1Ω
  
  Fig 1: Measuring Resistance Between Ground Terminal Of HO2S (S1) & Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
4. Is the measured resistance within specification?
  YES
  - Go to "COMPONENT INSPECTION " procedure.
  NO
  - Repair Open circuit , and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.