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. 1 (Nernst Voltage) and Channel A negative probe to Pin No. 4 (Trim Resistor).
4. Connect Channel B positive probe to Pin No. 3 (Virtual Ground) and Channel B negative probe to Pin No. 6 (Pumping Current).
   Fig 1: Screen Display - Approx. 2000 RPM (A), 3000 RPM (B) & Fuel Cut (C)

   Courtesy of KIA MOTORS AMERICA, INC.

   A and B: Approx. 2000 RPM and 3000 RPM

   CH.1 - Nernst Voltage & Trim Resistor: - 0.10 ~ 1.12 V

   CH.2 - Pumping Current & Virtual Ground: -0.35 ~ 0.59 V

   C: Fuel Cut

   CH.1 - Nernst Voltage & Trim Resistor: 1.10 V

   CH.2 - Pumping Current & Virtual Ground: 0.59 V

■ Confirm Part Inspection 

1. Does the HO2S (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 "System Inspection" procedure.