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Home >> Hyundai >> 2016 >> Sonata Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 2.4L (Except HEV) (1 Of 2) >> 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
  • Slow response (Switching time check at entry in fuel cut off)
  1. Leak in intake or exhaust system
  2. Faulty fuel system.
  3. Front and rear HO2S connections reversed.
  4. Poor connection or damaged harness
  5. HO2S contamination
Enable Conditions
  • O2 Sensor operative readiness
  • O2 Sensor preheating and full heating phases finished
  • Battery voltage between 11V and 16V
  • Mass flow integral out of pull cut off phase greater than 100g
  • Downstream O2 sensor readiness detected
  • Catalyst temperature model higher than 400°C (752°F)
  • Exhaust gas temperature model at sensor location higher than 400°C (752°F)
Threshold Value
  • Average ratio between measured and maximum allowed rich to lean switching time entering fuel cut-off more than 1
Diagnostic Time
  • 3 valid fuel cut-off phases
Mil On Condition
  • 2 Driving Cycles