how to resolve P0301 misfire code on BMW 3 Series F30/F31 (2012-2019)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Compression tester
• Multimeter
• Screwdrivers

2. Inspect and Replace Spark Plug

• Remove the engine cover if applicable.
• Disconnect the ignition coil connector for cylinder 1.
• Unscrew and remove the ignition coil using a socket.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or deposits; replace if necessary (OEM specifications).
• Install a new spark plug and torque to manufacturer specifications (typically around 20-30 Nm).

3. Inspect and Replace Ignition Coil

• If the spark plug is fine, test the ignition coil with a multimeter for proper resistance.
• If faulty, replace the ignition coil for cylinder 1 with a new unit.
• Reinstall the ignition coil and reconnect the electrical connector.

4. Check Fuel Injector

• Remove the fuel rail if necessary to access the fuel injector for cylinder 1.
• Test the injector for proper electrical function using a multimeter.
• If the injector is faulty, replace it and ensure proper seating in the fuel rail.

5. Perform Compression Test

• Remove the spark plug for cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds to get a reading.
• Compare the reading to the manufacturer’s specifications; if low, further inspection may be required.