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

Solution

1. Preparation

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

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts and gently pulling it out.
• Using a spark plug socket, carefully remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or damage; if it is worn, replace it with a new one (ensure it's the correct specification).
• Torque the new spark plug to the manufacturer's specifications (usually around 20 Nm).

3. Replace Ignition Coil

• If the ignition coil appears damaged, replace it with a new one.
• Install the new ignition coil on cylinder 1, ensuring it is seated properly.
• Reattach the connectors and screws to secure the coil in place.

4. Check Fuel Injector

• If the spark plug and ignition coil are in good condition, check the fuel injector for cylinder 1.
• Disconnect the fuel injector connector and use a noid light to check for signal while cranking the engine.
• If no signal is detected, inspect the wiring or replace the fuel injector if it is faulty.

5. Reassemble and Test

• Reconnect the battery.
• Start the engine and let it idle to ensure no misfires are present.
• Check for any error codes using the OBD-II scanner to confirm the P0301 code is cleared.