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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the spark plug from cylinder 2 using a socket wrench.
• Inspect the spark plug for wear, carbon buildup, or damage. If worn, replace it with a new spark plug that meets OEM specifications.
• Reinstall the spark plug and torque it to the manufacturer's specifications (typically around 13-15 lb-ft).

3. Test and Replace Ignition Coil

• Remove the ignition coil from cylinder 2 by unscrewing the mounting bolts and disconnecting the electrical connector.
• Use a multimeter to test the ignition coil’s resistance (consult the service manual for proper values).
• If out of specification, replace the ignition coil with a new one.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Disconnect the fuel injector connector and remove the fuel injector from cylinder 2.
• Inspect the injector for clogs or leaks; clean it using a suitable injector cleaner or replace it if necessary.
• Reinstall the fuel injector and reconnect the connector.

5. Check Engine Compression

• Remove the spark plug from cylinder 2 for compression testing.
• Use a compression gauge to measure the compression in cylinder 2. Compare results against manufacturer's specifications (typically 150-200 psi).
• If compression is low, further investigation into potential valve, piston, or head gasket issues is needed.