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P0309 Ford Code - Cylinder 9 Misfire Detected

- Code Popularity: 7,707 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC P0309 Ford?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty spark plug 9
  • Clogged or faulty fuel injector 9
  • Faulty ignition coil 9
  • Fuel injector 9 harness is open or shorted
  • Fuel injector 9 circuit poor electrical connection
  • Ignition coil 9 harness is open or shorted
  • Ignition coil 9 circuit poor electrical connection
  • Insufficient cylinder 9 compression
  • Incorrect fuel pressure
  • Intake air leak
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How to Fix the DTC P0309 Ford?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

The P0309 code means that cylinder #9 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder #9. If the problem persists more tests need to be done to diagnose the problem. See "Possible Causes" for the most common problems.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0309 Ford code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Lack/loss of power
  • Hard start
  • Engine hesitation

Code P0309 Ford Description

Misfire is defined as a lack of combustion in a cylinder due to the absence of a spark, incorrect fuel metering, low compression, or any other cause.
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.
The Malfunction Indicator Lamp (MIL) blinks once per second when detecting a misfire severe enough to cause catalyst damage. If the MIL is in a steady state due to a misfire, this indicates the threshold for emissions was exceeded and caused the vehicle to fail an inspection and maintenance tailpipe test.
This Diagnostic Trouble Code (DTC) sets when the misfire detection monitor detects an engine misfire in cylinder 9.

OBDII Code P0309 Ford - Cylinder 9 Misfire Detected - AutoCodes.com
P0309 Ford Code - Cylinder 9 Misfire Detected

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Code P0309 Ford comments

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