how to fix P0301 code in my BMW 5 Series G30/G31 (2017-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Remove Ignition Components

• Tools Required: Socket set, torque wrench
• Remove the engine cover (if applicable).
• Disconnect the electrical connectors from the ignition coil for cylinder 1.
• Unscrew and remove the ignition coil from cylinder 1.
• Remove the spark plug from cylinder 1 using a spark plug socket.

3. Inspect and Replace Components

• Check the spark plug for wear, carbon buildup, or damage. Replace if necessary (use OEM or equivalent).
• Inspect the ignition coil for cracks or signs of failure; replace if faulty.
• If the spark plug and ignition coil are in good condition, test the fuel injector for cylinder 1. If faulty, replace the fuel injector.
• If all components are functioning properly, proceed to check the compression of cylinder 1.

4. Compression Test

• Tools Required: Compression tester
• Insert the compression tester into the spark plug hole for cylinder 1.
• Crank the engine several times and record the compression reading.
• If the compression is below specifications, further diagnosis of the engine internals (valve or piston issues) is required.

5. Reassembly

• Reinstall the spark plug and ignition coil, ensuring proper torque specifications are followed (typically 15 Nm for spark plugs, check BMW specifications).
• Reconnect electrical connectors.
• Reinstall the engine cover.

6. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the codes.
• Start the engine and allow it to reach operating temperature.
• Conduct a test drive to ensure the vehicle operates smoothly and the check engine light remains off.