Component Inspection

■ HO2S Upstream (S1) Visual Inspection 

1. Ignition "OFF" and disconnect HO2S upstream (S1) connector.
2. Inspect HO2S upstream (S1) for contamination or damage caused by foreign materials.

■ HO2S Upstream (S1) Performance Inspection 

1. Warm up the engine to normal operating temperature.
2. Connect VMI to KDS/GDS and select "Oscilloscope".
3. Connect Channel A positive probe to Pin No. 6 (Pumping Current) and Channel A negative probe to Pin No. 4 (Trim Resistor).
4. Connect Channel B positive probe to Pin No. 1 (Nernst Voltage) and Channel B negative probe to Pin No. 3 (Virtual Ground).
   Fig 1: Screen Display - Approx. 2000 RPM (A) & Fuel Cut (B)

   Courtesy of KIA MOTORS AMERICA, INC.
   1. Approx. 2000 RPM

      CH.1 - Pumping Current & Virtual Ground: - 0.5 ~ 0.4 V

      CH.2 - Nernst Voltage & Trim Resistor: -1.0 ~ -0.0 V

   2. Fuel Cut

      CH.1 - Pumping Current & Virtual Ground: Approx. 0.89V

      CH.2 - Nernst Voltage & Trim Resistor: Approx. 0.64V

■ Confirm Part Inspection 

1. Does the HO2S upstream (S1) operate properly? (Check variation)

   YES 

   • Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Carefully re-do this troubleshooting guide steps.
   • If problem still occurs, replace HO2S upstream (S1) and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.