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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the ignition coil from cylinder 1 by disconnecting the electrical connector and unscrewing the mounting bolts.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear, carbon buildup, or damage. Replace if necessary.
• Install the new spark plug with a torque specification of 18 ft-lbs (24 Nm).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil by swapping it with a known good coil from another cylinder.
• If the misfire code moves to the other cylinder, replace the ignition coil.
• Install the new ignition coil and reconnect the electrical connector.

4. Check and Clean Fuel Injector

• If the misfire persists, use a fuel injector cleaner or replace the injector for cylinder 1.
• Disconnect the fuel injector electrical connector and remove the fuel rail if necessary to access the injector.
• Replace the fuel injector, ensuring proper sealing and connection.

5. Perform Compression Test

• If issues continue, perform a compression test on cylinder 1.
• If compression is below the manufacturer's specification, further diagnosis may be needed for potential internal engine issues.