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Home >> Hyundai >> 2017 >> Sonata Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System Diagnosis - 2.4L (1 Of 3) (Except HEV) >> DTC P0139-00: O2 Sensor Circuit Slow Response (Bank 1/Sensor 2) >> DTC Information >> DTC Description
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DTC Description

The PCM/ECM monitors rich-lean switching time of rear heated oxygen sensor (HO2S) after fuel cut-off to validate dynamic behavior of rear heated oxygen sensor (HO2S). After detection of fuel cut-off engine operating state, the PCM/ECM measures rich-lean switching time of the rear heated oxygen sensor (HO2S) signal and compares it to the predetermined limit value.

DTC P0139-00 is set when the switching time is bigger than the limit value.

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 11 V and 16 V
  • Mass flow integral out of pull cut off phase greater than 100 g
  • 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
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