LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Kia >> 2017 >> Optima Plug-In Hybrid EX >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Diagnosis (1 Of 3) (PHEV) >> DTC P0139-00: O2 Sensor Circuit Slow Response >> 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
  • Response Rate Monitoring
  1. Poor Connector Connection
  2. Air leak in Intake or Exhaust System
  3. Faulty Fuel system
  4. Faulty Downstream O2 Sensor
Enable Conditions
  • Downstream O2 sensor readiness detected
  • Downstream O2 sensor pre-heating phase finished
  • Catalyst temperature (model) is higher than 200°C (392°F)
  • Downstream O2 sensor signal at entry into fuel cut-off is higher than 0.6V
  • No relevant failure
  • Battery voltage is between 11V and 16V
Threshold Value
  • Downstream O2S voltage is lower than 800mV/s
Diagnostic Time
  • 3 valid fuel cut off phases
MIL ON Condition
  • 2 Driving Cycles