Component Inspection

■ Upstream HO2S Visual Inspection 

1. Ignition "OFF" and disconnect HO2S upstream (S1) connector.
2. Check that HO2S upstream (S1) is not contaminated or damaged by foreign materials.

■ Upstream HO2S 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: Scantool Display - Signal Waveform & Data (Approx 2000 RPM, 3000 RPM & Fuel Cut)

Courtesy of KIA MOTORS AMERICA, INC.

A and B: approx. 2000 RPM and 3000 RPM

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

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

C: Fuel cut

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

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

■ 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.