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Home >> Kia >> 2017 >> Niro EX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis (6 Of 6) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 / Sensor 1) >> Component Inspection >> Component Inspection
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Component Inspection

INSPECTION PART - O2 SENSOR (UP) COMPONENT SIDE INSPECTION

Inspection Condition (+) Probe (-) Probe Specification
Connector Terminal Connector Terminal
  1. Engine "ON" and Engine Idle.
O2 sensor (UP) component side 1 (Virtual Ground) O2 sensor (UP) connector 2 (Nernst Voltage) Fig 1
O2 sensor (UP) connector 3 (Current Pump) O2 sensor (UP) connector 4 (Current Adjust)
Fig 1: Screen Display - Normal Signal Waveform Of O2 Sensor (UP) At Engine WOT
G12330441Courtesy of KIA MOTORS AMERICA, INC.
Good 
  • Fault might be intermittent and caused either by poor contact in connectors or wiring harness, or it has been repaired and control module memory is not cleared yet. Thoroughly check terminal of battery, all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage. Repair or replace as necessary and then go to "Verification Of Repair " procedure.
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