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Home >> Hyundai >> 2021 >> Veloster N Standard Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (3 Of 3) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> Component Inspection >> HO2S Performance
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HO2S Performance

  1. Ignition switch is turned 'OFF'.
  2. Connect probe to signal terminal of HO2S (S1) connector and select oscilloscope function with GDS.
  3. Warm up the engine to normal operating temperature.
  4. Measure signal waveform of HO2S (S1) with GDS.

    Specification  : Refer to Signal Waveform & Data

  5. Is the measured signal waveform within specification?

    YES 

    • Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and Go to "Verification Of Repair " procedure.

    NO 

    • Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then Go to "Verification Of Repair " procedure.
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