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HOMESERVICE MANUALSKIA2015OPTIMA SX TURBOREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT VARIANT/TRIMSECTION 107 (ENGINE CONTROL SYSTEM DIAGNOSIS (2 OF 3) - 2.4L (EXCEPT HEV))DTC P0304: CYLINDER 4 - MISFIRE DETECTEDDTC INFORMATIONDTC DETECTING CONDITION
2015 Kia Optima SX Turbo

DTC Information: DTC Detecting Condition

2015 Kia Optima SX TurboSECTION DTC Detecting Condition
WARNING: This page is about a different variant/trim than selected.
DTC DETECTING CONDITION

Item Detecting Condition Possible Cause
DTC Strategy
  • Calculation of engine roughness
  1. Faulty spark plugs or Ignition coil
  2. Incorrect valve timing
  3. Uneven compression
  4. Air leakage
  5. Improper Fuel pressure or dirty fuel.
  6. Blocked/Leaking injectors
  7. Leakage between cooling system and cylinder
Enable Conditions
  • Engine load ratio : 14~64%
  • 500< Engine speed (RPM) <6700
  • Mass air flow gradient/sec. : 12~60%
  • Throttle gradient/sec. : 0.5~10.5%
  • Coolant temperature >20°C (68°F) if start temp. < -7°C (19°F)
  • No relevant failure
  • Fuel cut-off not active
  • 11V< Battery voltage <16V
Threshold Value Case 1
  • Misfire ratio : 9.1 % - 50 % within 200 rev.
Case 2
  • Misfire ratio : 2.3% within 1, 000 rev.
Diagnosis Time Case 1
  • 200 rev. or 3*200 rev.
Case 2
  • 1000 rev. or 4*1000 rev.
MIL On Condition Case 1
  • Immediate
Case 2
  • 2 Drive Cycles
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.