Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

SYS.OK|MANUAL.DB● LIVE

HOMESERVICE MANUALSHYUNDAI2011TUCSON GL, AUTOMATICREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROL SYSTEM DIAGNOSIS (1 OF 2)DTC P0303: CYLINDER 3 - MISFIRE DETECTEDGENERAL INFORMATIONDTC DETECTING CONDITION

2011 Hyundai Tucson GL, Automatic

General Information: DTC Detecting Condition

2011 Hyundai Tucson GL, AutomaticSECTION DTC Detecting Condition

DTC DETECTING CONDITIONS

Item		Detecting Condition	Possible Cause
DTC Strategy		Calculation of engine roughness	Faulty spark plugs or Ignition coil Incorrect valve timing Uneven compression Air leakage Improper Fuel pressure or dirty fuel. Blocked/Leaking injectors 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.
Threshold Value	Case 2	Misfire ratio: 2.3% within 1, 000 rev.
Diagnosis Time	Case 1	200 rev. or 3*200 rev.
Diagnosis Time	Case 2	1000 rev. or 4*1000 rev.
MIL On Condition	Case 1	Immediate
MIL On Condition	Case 2	2 Driving Cycles

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

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.