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Home >> Kia >> 2019 >> Optima EX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 1.6L (2 Of 6) (Except HEV) >> DTC P0139: O2 Sensor Circuit Slow Response (Bank 1/Sensor 2) >> DTC Information >> DTC Detecting Condition
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DTC Information: DTC Detecting Condition

Item Detecting Condition Possible Cause
DTC Strategy
  • Transient time monitor (Rich to Lean)
  1. Poor connection
  2. Open or Short to ground in power circuit
  3. Damaged or corroded terminals
  4. HO2S (S2)
Enable Conditions
  • Dew point end detected
  • Battery voltage is greater than 11V
  • Exhaust Gas temperature is 350°C (662°F) to 800°C (1472°F)
  • No downstream O2 sensor heater error
  • Integrated air mass during fuel cut-off is greater than 0.62kg-0.78kg
  • Downstream O2 sensor monitoring completed
  • No downstream O2 sensor error detected
  • Downstream O2 sensor heater monitoring completed
  • No misfire
  • No fuel system error
  • No PCV error
  • No CKP sensor error
  • No CMP sensor error
Threshold Value
  • O2 sensor voltage is greater than 0.15V
Diagnostic Time
  • 2s
MIL ON Condition
  • 3 driving cycles

* S1: upstream oxygen sensor/S2: downstream oxygen sensor