P0304 2009 Ford Fusion Code - Cylinder 4 Misfire Detected
Quick Answer
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. Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0304 2009 Ford Fusion indicates Cylinder 4 Misfire Detected.
- Common causes
- Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0304 2009 Ford Fusion Description
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 4.
What are the Possible Causes of the DTC P0304 2009 Ford Fusion?
- Faulty Spark Plug #4
- Clogged or faulty Fuel Injector #4
- Faulty Ignition Coil #4
- Fuel Injector #4 harness is open or shorted
- Fuel Injector #4 circuit poor electrical connection
- Ignition Coil #4 harness is open or shorted
- Ignition Coil #4 circuit poor electrical connection
- Insufficient cylinder 4 compression
- Incorrect fuel pressure
- Intake air leak
How to Fix the DTC P0304 2009 Ford Fusion?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0304 2009 Ford Fusion code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0304 2009 Ford Fusion Code
1. What does OBDII code P0304 mean for a 2009 Ford Fusion?
- OBDII code P0304 on a 2009 Ford Fusion specifically indicates a misfire in cylinder 4 of the engine.
2. What are common symptoms of a cylinder 4 misfire in a 2009 Ford Fusion?
- Common symptoms of a cylinder 4 misfire in a 2009 Ford Fusion may include rough idle, loss of power, engine vibrations, and potentially increased fuel consumption.
3. What are some possible causes of a cylinder 4 misfire in a 2009 Ford Fusion?
- Possible causes of a cylinder 4 misfire in a 2009 Ford Fusion include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, or issues with the engine's compression.
4. How can I diagnose a cylinder 4 misfire in my 2009 Ford Fusion?
- To diagnose a cylinder 4 misfire in a 2009 Ford Fusion, you can use an OBDII scanner to read the code, inspect spark plugs and ignition coils, check fuel injectors, and perform a compression test.
5. What are some repair tips for fixing a cylinder 4 misfire in a 2009 Ford Fusion?
- Repair tips for fixing a cylinder 4 misfire in a 2009 Ford Fusion may include replacing faulty spark plugs, ignition coils, or fuel injectors, fixing any vacuum leaks, and ensuring proper engine compression.
6. Can driving with a cylinder 4 misfire in a 2009 Ford Fusion cause further damage?
- Continuing to drive with a cylinder 4 misfire in a 2009 Ford Fusion can potentially cause damage to the catalytic converter, oxygen sensors, or other engine components due to unburned fuel entering the exhaust system.
7. How much does it typically cost to repair a cylinder 4 misfire in a 2009 Ford Fusion?
- The cost of repairing a cylinder 4 misfire in a 2009 Ford Fusion can vary depending on the exact cause of the issue, but it may range from around $100 for simple fixes like spark plug replacement to several hundred dollars for more complex repairs.
8. Can I reset the OBDII code P0304 in my 2009 Ford Fusion without fixing the underlying issue?
- While you can clear the OBDII code P0304 in a 2009 Ford Fusion with an OBDII scanner, it is not recommended to do so without addressing the underlying cause of the cylinder 4 misfire, as the issue may persist and potentially lead to further damage.
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