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P0309
System
Powertrain (Engine)
Scanner som krävs
Basic OBD2 code reader (engine codes, live data, smog readiness)

Cylinder 9 Misfire Detected

Understand P0309, common causes, and the right TOPDON scanner to diagnose it.

Misfire detected on cylinder 9 — same diagnostics as P0301–P0308 but for engines with more than eight cylinders or specific bank layouts.

Vanliga symptom

  • Rough idle
  • Power loss
  • May set with P0300

Typiska orsaker

  • Ignition coil or plug on cylinder 9
  • Injector fault
  • Low compression
  • Vacuum leak affecting that runner

Vilken scanner behöver du?

Basic OBD2 code reader (engine codes, live data, smog readiness)

Använd live-data och freeze frame innan du byter delar. ABS-, SRS- och U-koder kräver oftast en fullsystems-scanner.

Diagnostiktips

  • Spara freeze frame när koden först sätts
  • Rensa koden först efter att orsaken är åtgärdad
  • Kontrollera relaterade väntande koder
  • Verifiera batterispänning över 12,4 V innan du misstänker sensorer

Rekommenderade TOPDON-scannrar

Vanliga frågor

What does P0309 mean?
P0309 indicates cylinder 9 misfire detected. Misfire detected on cylinder 9 — same diagnostics as P0301–P0308 but for engines with more than eight cylinders or specific bank layouts.
Can I diagnose P0309 with a basic code reader?
Yes — P0309 is typically accessible with a basic OBD2 code reader like the TOPDON ArtiDiag201 or TopScan Lite. Live data helps confirm the repair.
Which TOPDON scanner do I need for P0309?
Basic OBD2 code reader (engine codes, live data, smog readiness) See recommended tools on this page.
Is it safe to drive with P0309?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.