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Home >> Hyundai >> 2017 >> Sonata Plug-In Hybrid >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (PHEV) (3 Of 3) >> DTC P2251: 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 check
  1. Poor connection or damaged harness
  2. Open in HO2S control circuit
  3. Front HO2S
Enable Conditions
  • Battery voltage is between 11V and 16V
  • Upstream O2 sensor operative readiness is detected
Threshold value
  • Signal voltage is between 1.9V and 2.1V for 5sec during internal test
  • Reference ground circuit open (VG)
  • Signal voltage is lower than 2.1V during fuel cut off
Diagnosis Time
  • 15 sec.
MIL On Condition
  • 2 Driving Cycles
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