why is my BMW 3 Series G20/G21 (2019-2024) giving me a P0301 code?

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the battery to avoid any electrical shorts.
• Ensure the engine is cool before starting.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts and lifting it off.
• Carefully remove the spark plug with a spark plug socket and ratchet. Inspect the old spark plug for wear or damage.
• Install a new spark plug, ensuring it is gapped correctly according to manufacturer specifications (typically around 0.028-0.031 inches for BMW).
• Torque the spark plug to the manufacturer’s specified value (usually around 20 Nm).

3. Inspect and Replace Ignition Coil

• If the spark plug is not the issue, test the ignition coil for functionality using a multimeter.
• If faulty, replace the ignition coil with a new unit.
• Reinstall the ignition coil onto the new spark plug, ensuring it is firmly seated and secured.

4. Clean Fuel Injector

• If the ignition components are functioning correctly, remove the fuel injector from cylinder 1.
• Clean the injector using an appropriate fuel injector cleaner or replace it if necessary.
• Reinstall the fuel injector, ensuring proper seating and connection to the fuel rail.

5. Reassemble and Reconnect

• Reattach any components removed during the process, ensuring all connections are secure.
• Reconnect the battery.