how to fix P0302 code in BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Disconnect the electrical connector from the ignition coil on cylinder 2.
• Remove the ignition coil by pulling it straight up.
• Use a spark plug socket to remove the spark plug from cylinder 2.
• Inspect the new spark plug and ensure it is gapped according to manufacturer specifications.
• Install the new spark plug and torque it to the manufacturer's specification (typically around 15-20 Nm).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test/Replace Ignition Coil

• If misfire persists, test the ignition coil using a multimeter (primary and secondary resistance).
• If faulty, replace with a new ignition coil specific to the BMW F30/F31.
• Reconnect the ignition coil.

4. Inspect/Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Remove the injector retaining clips and gently pull out the injector.
• Test the injector with a multimeter or swap with a known working injector to check for function.
• If defective, replace with a new fuel injector compatible with the BMW F30/F31.

5. Final Checks

• Reconnect any components removed during the repair.
• Reconnect the negative battery terminal.
• Start the engine and check for smooth operation.