Signal Circuit Inspection

■ Check 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 Nernst Voltage terminal of HO2S (S1) harness connector and chassis ground.

   Measure the voltage between Virtual Ground Output terminal of HO2S (S1) harness connector and chassis ground.

   Measure the voltage between Current Adjust terminal of HO2S (S1) harness connector and chassis ground.

   Measure the voltage between Current Pump terminal of HO2S (S1) harness connector and chassis ground.

   Specification: 

   Nernst Voltage: Approx 2.9V

   Virtual Ground Output: Approx 2.5V

   Current Adjust: Approx 2.8V

   Current Pump: Approx 2.8V

   Fig 1: Measuring Voltage Between Current Pump Terminal Of HO2S (S1) Harness Connector And Chassis Ground

   Courtesy of KIA MOTORS AMERICA, INC.
   Fig 2: Current Pump Connector Terminal

   Courtesy of KIA MOTORS AMERICA, INC.
5. Is the measured voltage within specification?

   YES 

   • Go to "COMPONENT INSPECTION " procedure.

   NO 

   • Repair Open or Short circuit and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.