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Home >> Kia >> 2019 >> Optima EX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 1.6L (6 Of 6) (Except HEV) >> DTC P2251: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> Component Inspection >> Check HO2S (S1) performance
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Check HO2S (S1) performance

  1. Warm up the engine to normal operating temperature.
  2. Connect VMI to KDS 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).
G12922911Courtesy of KIA MOTORS AMERICA, INC.

A: Approx. 2000rpm

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

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

B: Fuel Cut

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

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