Component Inspection

■ Heated Oxygen Sensor (HO2S) Upstream (S1) 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.

■ 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.