P0309 OBD-II Trouble Code: Cylinder 9 Misfire Detected

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0309 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0309 code

P0309 is a diagnostic trouble code (DTC) for "Cylinder 9 Misfire Detected". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0309 DIAGNOSTIC Get a fair and transparent estimate upfront

P0209 code definition

When the P0209 trouble code appears, it means that the powertrain control module has found a misfire from cylinder number 9.

What the P0209 code means

When this code appears, it means that the vehicle’s computer has found one of the engine cylinders is not firing properly.

What causes the P0209 code?

Potential causes of the trouble code:

  • Burned exhaust valve
  • Faulty catalytic converter
  • Poor compression
  • Running out of fuel
  • Faulty coil
  • Faulty oxygen sensor
  • Faulty fuel injector
  • Faulty wiring
  • Faulty spark plug
  • Defective onboard computer, although this is rare

What are the symptoms of the P0209 code?

There are a number of symptoms that could be caused by the P0209 code. In many cases, the service engine soon lamp will illuminate. In addition to the stored code, the vehicle may have a rough idle and the acceleration may feel choppy. The driver may also notice that there is a reduced amount of power in the vehicle. Some also find that the vehicle is more difficult to start.

How does a mechanic diagnose the P0209 code?

When the mechanic is trying to diagnose the P0209 code, he or she will attach their OBD-II scanner to the vehicle’s onboard computer. They will then scan for the code and any other codes that may be stored in the vehicle. At that point, they will reset the code and drive the vehicle to see if the codes return.

If the code returns, then they know it is a problem that they will need to fix. They will then start to look at all the other potential problems that could be causing the code to be stored, such as faulty fuel injectors, bad wiring, or a problematic catalytic converter.

Common mistakes when diagnosing the P0209 code

When this code presents itself, some mechanics may believe that the problem lies in the ignition system rather than other areas. While it is possible for the ignition system to be a fault, there are also other factors that could cause this misfire of the cylinder. It is important for the mechanics to look at all of the potential areas that could be causing problems and find the correct solution for the vehicle.

How serious is the P0209 code?

While the stored code and a service light that illuminates might not seem like a big problem, there are other potential issues with the P0209 code. Drivers who are in vehicles that do not accelerate properly when they are driving could be in danger. Any vehicle that is not performing properly has the potential to cause an accident. The best course of action is to take the vehicle to a mechanic who can diagnose it and make the proper repairs. This is true no matter what code has been stored.

What repairs can fix the P0209 code?

The following are some of the potential fixes that mechanics will attempt when trying to deal with the misfired cylinder number 9.

Additional comments for consideration regarding the P0209 code

The P0209 code, as with all trouble codes, is nothing to ignore. Take the vehicle to a mechanic to have it diagnosed and repaired properly as soon as possible.

Need help with a P0209 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6220.

trouble codes
P0309
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0309 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,810

Rating Summary
4,424
187
47
28
124
4,424
187
47
28
124

Joel

19 years of experience
741 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.

Christopher

15 years of experience
41 reviews
Christopher
15 years of experience
Honda Accord - Check Engine Light is on - Fairburn, Georgia
Christopher was excellent! He explained everything in detail to make sure I understood. He was professional and provided me with the next course of actions to resolve my care issues. I'm glad he was sent to service my car.

Alexander

18 years of experience
58 reviews
Alexander
18 years of experience
Saab 9-7x - Check Engine Light is on - Kissimmee, Florida
He was very friendly and very helpful . I felt like it was being around a close friend , also gave me so very good advice on my car & future advice about it . Highly recommend mechanic, would use his services again .

Matthew

31 years of experience
639 reviews
Matthew
31 years of experience
Jeep Patriot - Check Engine Light is on - Norfolk, Virginia
Matthew was on time which was a relief, he is very knowledgeable and was easy to understand what was wrong and what was being done. I am recommending to friends and family due to the great experience Matthew gave me. Extremely professional 10/10

More related articles

P2667 OBD-II Trouble Code: Fuel Shutoff Valve B Control Circuit High
P2667 means there is a problem with the fuel shut off valve usually after a rear end collision or other electrical issues or problem.
P0454 OBD-II Trouble Code: Evaporative Emission Control System Pressure Sensor Intermittent
P0454 means there is an issue with the evaporative emission control system due to faulty fuel cap, solenoid, or broken hoses, canister, or vacuum.
P3446 OBD-II Trouble Code: Cylinder 6 Exhaust Valve Control Performance
P3446 means certain cylinders were shut down during specific driving conditions due to low oil pressure, faulty lifters or varied sensors.

Related questions

Hello, my car has no spark, no controlled ground for the fuel pump, and no injector pulse. Fuse link close to the battery and relays are good.

Hello and thank you for contacting YourMechanic. The ECU is under your passenger's side seat. You can gain access to it by simply sliding the seat all the way forward and removing the plastic cover from the ECU. You can...

My van was missing and rough idling then I turned it off one day and the next day it starts then dies and some times it won't start

Hello, thanks for writing in about your 2001 Dodge Caravan. For certain, given your mileage and codes for these 2 components, replacing these 2 sensors is the minimum. Cleaning the idle air control valve, throttle body, and PCV valve should...

Check Engine Light is On.

The transmission light flashing 16 times may be a problem with the DC solenoid for lock up and the transmission defaults to AWD causing the jerking on turns. I recommend you get a qualified mechanic check and scan the vehicle's...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com