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. 3 (Pumping Current) and Channel A negative probe to Pin No. 6 (Trim Resistor).
4. Connect Channel B positive probe to Pin No. 2 (Nernst Voltage) and Channel B negative probe to Pin No. 1 (Virtual Ground).

Fig 1: Scantool Display - Signal Waveform & Data (Approx 2000RPM & Fuel Cut)

Courtesy of KIA MOTORS AMERICA, INC.

A: Approx. 2000RPM

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

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

B: 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 "System Inspection" procedure.