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Home/Cars/Ford/F-150/13th Generation (2015-2020)/how to diagnose P0303 misfire code on Ford F-150 13th Generation (2015-2020)

how to diagnose P0303 misfire code on Ford F-150 13th Generation (2015-2020)

Ford F-150 13th Generation (2015-2020)

Error Codes
Severity: highDifficulty: mediumError Code: P03032-4 hours
3 min read
579 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix P0303 cylinder 3 misfire in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0303
Affected Component
Engine
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems to avoid shorts.
  • ⚠Allow the engine to cool before performing any repairs to avoid burns.

Symptoms

  • •Check engine light illuminated
  • •Rough idle or hesitation during acceleration
  • •Decreased engine performance or power
  • •Poor fuel economy
  • •Increased exhaust emissions
  • •Engine stalling or hesitation

Diagnostic Steps

  1. 1Scan the vehicle's onboard computer using an OBD-II scanner to confirm the P0303 code and check for any additional codes.
  2. 2Inspect the spark plug for cylinder 3 for wear, damage, or incorrect gap.
  3. 3Check the ignition coil associated with cylinder 3 for proper resistance and functionality.
  4. 4Perform a compression test on cylinder 3 to verify mechanical integrity.
  5. 5Inspect fuel injectors for clogs or proper operation using a noid light or fuel pressure gauge.
  6. 6Check for vacuum leaks in the intake manifold or around the throttle body that could affect cylinder 3.
  7. 7Perform a visual inspection of the wiring and connectors related to the ignition coil and fuel injector for damage or corrosion.

Solution

Solution

1. Preparation

  • Gather necessary tools and parts.
  • Ensure the vehicle is parked on a level surface and the engine is off.
  • Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug

  • Remove the engine cover (if applicable) using a socket set.
  • Locate cylinder 3 spark plug and remove the ignition coil by unbolting it and disconnecting the electrical connector.
  • Unscrew the spark plug using a spark plug socket and ratchet.
  • Inspect the old spark plug for wear; install a new spark plug with the correct gap per manufacturer specifications.
  • Reinstall the ignition coil and cover.

3. Replace Ignition Coil

  • If the ignition coil was found faulty during diagnostics, remove it from the cylinder 3.
  • Install a new ignition coil, ensuring it is seated properly.
  • Reconnect the electrical connector securely.

4. Inspect and Clean Fuel Injector

  • Remove the fuel rail (if necessary) to access the injector for cylinder 3.
  • Inspect the fuel injector for clogs and clean or replace if necessary.
  • Reinstall the fuel rail and reconnect all lines and connectors.

5. Check Compression

  • If compression was low, perform a cylinder head gasket replacement or other necessary repairs based on findings.
  • Recheck compression after repairs to ensure it meets manufacturer specifications.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II scanner
  • •Socket set
  • •Torque wrench
  • •Compression tester
  • •Fuel pressure gauge
  • •Noid light

Parts Required

  • •Spark plug (specific to engine specifications)
  • •Ignition coil (specific to cylinder 3)
  • •Fuel injector (if faulty)

Additional Information

Error Code
P0303
Affected Component
Engine
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
6 items
Parts Required
3 items

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