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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, spark plug socket, compression tester, fuel injector cleaner, hand tools.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Check and Replace Spark Plug

• Remove the engine cover if applicable.
• Disconnect the ignition coil connector and remove the ignition coil from cylinder 2.
• Using a spark plug socket, remove the spark plug from cylinder 2.
• Inspect the spark plug for wear (burnt or fouled) and replace if necessary with an OEM equivalent (torque to specifications).
• Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coil

• If the spark plug is fine, replace the ignition coil on cylinder 2.
• Disconnect the battery to avoid electrical shorts.
• Remove the faulty ignition coil and install the new ignition coil (ensure proper seating).
• Reconnect the battery.

4. Compression Test

• Remove spark plug from cylinder 2.
• Insert compression tester and crank the engine.
• Record the compression reading; it should be within specifications (consult service manual).
• If compression is low, further diagnosis will be required for internal engine issues.

5. Fuel Injector Cleaning or Replacement

• If spark plug and ignition coil are good, check the fuel injector.
• Disconnect the fuel injector connector and remove the injector.
• Use a fuel injector cleaner to clean the injector or replace it if necessary.
• Reinstall the injector and reconnect the fuel injector connector.