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Home >> Hyundai >> 2021 >> Palisade Calligraphy, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (9 Of 9) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> DTC Information and Inspection >> DTC Detecting Condition
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DTC Information and Inspection: 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 Condition
  • Upstream O2 sensor operative readiness is detected
  • Battery voltage higher than 11V and lower than 16V
Threshold Value
  • Reference virtual ground circuit open (Vg)
  • Inactivity Inspection
    • Nernst voltage (Vn) is higher than 4.4V or
    • Difference between pumping current circuit (Vip) voltage and virtual ground (Vg) voltage is higher than 2.1V or lower than -2.0V or
    • Difference between nernst voltage (Vn) voltage and virtual ground (Vg) voltage is higher than 1.9V or lower than -0.1V or
    • Pumping current is higher than 11.5 mA and as per the activity Inspection below,
  • Activity Inspection
    • Difference between pumping current circuit (Vip) voltage and virtual ground (Vg) voltage is higher than 1.2V or
    • Difference between nernst voltage (Vn) voltage and virtual ground (Vg) voltage is lower than 1.2V
Diagnostic Time
  • 2.5 sec.
MIL ON Condition
  • 2 Driving Cycles
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