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Home >> Kia >> 2017 >> Rio SX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis (1 Of 3) >> DTC P0139: O2 Sensor Circuit Slow Response (Bank 1/Sensor 2) >> General Information >> DTC Detecting Condition
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General Information: DTC Detecting Condition

Item Detecting Condition Possible Cause
DTC Strategy
  • Monitor signal voltage
  1. Poor connection
  2. S2
  3. ECM
General Enable Conditions
  • Downstream O2S voltage before fuel cut > 0.55V
  • Fuel cut off
  • EGT around downstream O2S > 662°F
  • Downstream O2S internal resistance
  • Battery voltage > 10.7V
  • Time after dew point end detected > 30 sec
Case1 Enable Conditions
  • Exhaust gas mass flow > 30 kg/h
Threshold Value
  • Response Time > 5.0 sec

    (Duration of Downstream O2S voltage from above 0.55V to 0.15V during fuel cut off)
Case2 Enable Conditions
  • Exhaust gas mass flow > 10 kg/h
Threshold Value
  • Transient Time > 0.3 sec

    (Duration of Downstream O2S voltage from 0.4V to 0.2V during fuel cut off)
MIL On Condition
  • 2 Driving Cycles
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