LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Kia >> 2021 >> K5 GT-Line, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 1.6L (6 Of 7) >> DTC P2251-00: O2 Sensor Reference Ground Circuit/Open (Bank 1 Sensor 1) >> DTC Information >> DTC Detecting Condition
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC Information: DTC Detecting Condition

Item Detecting Condition Possible Cause
DTC Strategy
  • Open in circuit
  • Poor connector connection
  • Open in upstream O2 sensor control circuit
  • Defected upstream O2 sensor
Enable Conditions
  • Internal resistance higher than 950Ω
  • Internal resistance signal is valid
Threshold Value
  • Sensor voltage is between 2.3 and 2.7V
Diagnostic Time
  • 5s
Mil On Condition
  • 2 driving cycles