how to fix P0302 code in my BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery (negative terminal) to ensure safety during repair.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket, gap tool
• Remove the ignition coil for cylinder 2 by unbolting it and disconnecting the electrical connector.
• Extract the spark plug using a spark plug socket. Inspect for wear, carbon buildup, or damage.
• If necessary, replace the spark plug with a new one, ensuring it is gapped correctly according to manufacturer specifications.
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if needed)

• Tools Required: Multimeter (for testing)
• If the spark plug appears normal, test the ignition coil for proper resistance using a multimeter.
• If the ignition coil is faulty, remove it from cylinder 2 and replace it with a new one. Reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaner, cleaning kit
• Remove the fuel injector for cylinder 2 by detaching the fuel rail and electrical connector.
• Inspect the injector for clogs or carbon build-up. Clean using a fuel injector cleaning kit; if it does not clean effectively, replace the injector with a new one.
• Reinstall the fuel injector and reconnect it to the fuel rail and electrical connector.

5. Verify Engine Compression

• Tools Required: Compression tester
• Perform a compression test on cylinder 2. If readings are low, further investigation may be needed for internal engine issues like valve problems or head gasket failure.

6. Final Checks

• Reconnect the vehicle's battery.
• Start the engine and monitor for any abnormal sounds or behaviors.