P0309
Cylinder 9 Misfire Detected
P0309 is an OBD-II diagnostic trouble code meaning: Cylinder 9 Misfire Detected. Common causes: faulty spark plug, problems with the ignition coil. Estimated repair cost: $56–222.
Symptoms
- Engine troubles
- Power Loss
- Increased fuel consumption
- Unstable idle
- Jerking during acceleration
Causes
- Faulty spark plug
- Problems with the ignition coil
- Fuel injector malfunction
- Low cylinder compression
- Problems with sensors (mass air flow sensor, knock sensor)
- Vacuum leak
- Malfunction of the variable valve timing (VVT) system
How to Fix
- Check the condition of the spark plug in cylinder 9
- Check the ignition coil
- Check the operation of the fuel injector
- Measure the compression in the cylinder
- Check the condition of the wiring harness
- Check the operation of the sensors (mass air flow sensor, knock sensor)
- Check the intake manifold for leaks
- Check VVT system
Related codes
Error P0309 by Vehicle Brand
FAQ
What does the P0309 code mean?
P0309 is an OBD-II diagnostic trouble code that indicates: Cylinder 9 Misfire Detected
What causes a P0309 error code?
The most common causes of P0309 include: Faulty spark plug; Problems with the ignition coil; Fuel injector malfunction; Low cylinder compression.
How do I fix a P0309 diagnostic trouble code?
To fix P0309: Check the condition of the spark plug in cylinder 9. Check the ignition coil. Check the operation of the fuel injector. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0309?
Limited driving only, diagnose soon
How much does it cost to fix P0309?
The estimated repair cost for P0309 is $56–222. Actual cost depends on your vehicle, location, and labor rates.
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