what does the P0301 code mean for my BMW 5 Series F10/F11 (2010-2017) and how to fix it?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool down completely.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil for cylinder 1.
• Use a spark plug socket to remove the spark plug.
• Inspect the old spark plug for fouling or damage, and replace it with a new one.
• Torque the new spark plug to the manufacturer’s specifications (typically around 16 lb-ft).
• Reinstall the ignition coil.

3. Test or Replace Ignition Coil

• Tools Required: Multimeter.
• Use a multimeter to test the ignition coil's resistance and compare it to specifications.
• If the coil is faulty, replace it with a new one, ensuring that it is compatible with your BMW model.
• Reconnect the ignition coil to the spark plug.

4. Inspect and Clean Fuel Injector

• Tools Required: Injector cleaning kit (if necessary), or replace the injector.
• Remove the fuel injector from cylinder 1.
• Inspect for clogs or damage; clean or replace the injector as needed.
• Reinstall the fuel injector and reconnect fuel lines.

5. Conduct Compression Test

• Tools Required: Compression gauge.
• Remove the spark plug from cylinder 1.
• Insert the compression gauge into the spark plug hole.
• Crank the engine to take a reading; ensure it is within manufacturer specifications (typically around 120-200 psi).
• If compression is low, further investigation into engine internals may be necessary.