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Home >> Kia >> 2019 >> Optima EX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis (5 Of 6) (PHEV) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> DTC Information >> DTC Detecting Condition
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DTC Information: DTC Detecting Condition

Item Detecting Condition Possible cause
DTC Strategy
  • Electrical Monitoring
  1. Poor Connector Connection
  2. Open in Upstream O2 Sensor Control Circuit
  3. Faulty Upstream O2 Sensor
Enable Conditions
  • Sensor Pump Current Valid
  • Battery voltage higher than 11V and lower than 16V
Threshold Value
  • Reference ground circuit open (VG)
Diagnostic Time
  • Within 15s after related symptom detected
Mil On Condition
  • 2 Driving Cycles
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