how to diagnose misfire code P0302 on Ford F-150 12th Generation (2009-2014)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shock.
• Ensure the engine is cool before working on it.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil and spark plug from cylinder 2.
  2. Inspect the spark plug for wear, carbon buildup, or damage; replace it if necessary.
  3. Check and adjust the spark plug gap to the manufacturer specifications (typically around 0.054 inches for Ford F-150).
  4. Reinstall the spark plug and ignition coil.

3. Test and Replace Ignition Coil

• Sub-steps:
  1. Use a multimeter to measure the resistance of the ignition coil; it should be within the specified range.
  2. If the coil is faulty, remove it and replace it with a new one.
  3. Reconnect the ignition coil and ensure all connections are secure.

4. Fuel Injector Inspection and Replacement

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 2 and check for continuity using a multimeter.
  2. If the injector is not functioning, remove it using an injector puller.
  3. Replace it with a new injector and reconnect the wiring.
  4. Reconnect the fuel injector connector.

5. Compression Testing

• Sub-steps:
  1. Remove the spark plug from cylinder 2.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine for a few seconds and record the compression reading; it should be within the manufacturer’s specifications (usually around 120-160 psi).
  4. If compression is low, further diagnostic work may be needed for internal engine issues.