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Home >> Kia >> 2017 >> Forte LX, Automatic Trans >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 2.0L MPI Nu (1 Of 3) >> DTC P0140: O2 Sensor Circuit No Activity Detected (Bank 1/Sensor 2) >> Component Inspection
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Component Inspection

■ Visual Check HO2S (B1S2) 

  1. Ignition "OFF" and disconnect HO2S (B1S2) connector.
  2. Check HO2S (B1S2) for contamination or damaged by foreign materials.

■ Check HO2S (B1S2) performance 

  1. Warm up the Engine to normal operating temperature.
  2. Connect VMI to KDS/GDS and select "Oscilloscope".
  3. Connect CH A (+) probe to signal terminal (Pin No. 1) of HO2S (B1S2) connector.
  4. Connect CH A (-) probe to ground terminal (Pin No. 2) of HO2S (B1S2) connector.

    Specification:  Refer to Fig 1

    Fig 1: Screen Display - Signal Waveform Of HO2S (B1S2) At Normal Condition
    G12150705Courtesy of KIA MOTORS AMERICA, INC.

■ Confirm Part Inspection 

  1. Does the HO2S (B1S2) operate properly? (Check variation)

    YES 

    NO 

    • Carefully re-do this troubleshooting guide steps.
    • If no problems were found with the circuits or connectors, replace the HO2S (B1S2) and go to "Verification of Vehicle Repair " procedure.