how to fix BMW 3 Series F30/F31 (2012-2019) error code P0301

Solution

1. Preparation

• Gather tools and materials: OBD-II scanner, compression tester, spark plug socket, torque wrench, ignition coil puller, fuel injector cleaning kit.
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Remove Spark Plug and Ignition Coil

• Disconnect the negative battery terminal to prevent electrical shorts.
• Remove the engine cover if applicable.
• Carefully disconnect the ignition coil connector from the ignition coil.
• Unscrew the ignition coil using the socket set and remove it from the cylinder head.
• Use the spark plug socket to remove the spark plug from cylinder 1.

3. Inspect and Replace Components

• Check the spark plug for wear, carbon buildup, or damage; replace if necessary (recommended spark plug gap: 0.028-0.032 inches).
• Inspect the ignition coil for cracks or signs of failure; replace if damaged.
• If the spark plug and coil are in good condition, test the fuel injector operation. If it’s faulty, replace the injector.

4. Conduct Compression Test

• Insert the compression tester into the spark plug hole and crank the engine for a few seconds.
• Record the compression reading; it should be within manufacturer specifications (typically around 140-200 psi).
• If the compression is low, investigate further for potential internal engine problems.

5. Reassemble and Test

• Reinstall the spark plug with the correct torque value (typically around 15-20 ft-lbs).
• Reinstall the ignition coil and reconnect the electrical connector.
• Reconnect the battery terminal and start the engine, checking for any error codes.