how to fix P0300 code in BMW 5 Series G30/G31 (2017-2024)

Solution

1. Preparation

• Gather tools and parts required for repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coils by unscrewing the bolts and lifting them out.
• Use a spark plug socket to remove each spark plug.
• Inspect the old spark plugs for wear or damage and replace them with new ones, ensuring they are gapped properly according to specifications.
• Torque the new spark plugs to the manufacturer’s specifications (typically around 15 lb-ft).

3. Replace Ignition Coils (if needed)

• If ignition coils show signs of damage or poor performance, replace them.
• Install new ignition coils by seating them properly over the new spark plugs and securing them with bolts.
• Reconnect the electrical connectors to each ignition coil.

4. Inspect and Clean Fuel Injectors

• Tools Required: Fuel injector cleaner, fuel pressure gauge.
• If fuel delivery is suspected to be an issue, remove the fuel injectors for cleaning or replacement.
• Use a fuel injector cleaning kit or take them to a professional for ultrasonic cleaning.
• Reinstall injectors ensuring proper seating and securing clips.

5. Check and Repair Vacuum Leaks

• Inspect all vacuum lines and connections for cracks or disconnections.
• Replace any damaged hoses or reconnect loose connections.
• For persistent leaks, consider using a smoke machine to identify difficult-to-find leaks.

6. Final Assembly and Battery Reconnection

• Reassemble any removed components.
• Reconnect the negative battery terminal.
• Clear the error codes using the OBD-II scanner.