how to fix the P0301 misfire code on 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 before beginning work.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Unplug the electrical connector.
  • Unscrew the bolt securing the coil.
  • Gently pull the coil out.
• Remove the spark plug:
  • Use a spark plug socket to unscrew and remove the old spark plug.
• Install the new spark plug:
  • Apply anti-seize compound to the threads (if recommended).
  • Torque the new spark plug to manufacturer specifications (typically 22 Nm).
• Reinstall the ignition coil:
  • Ensure the coil is seated properly and secure it with the bolt.
  • Reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil shows signs of damage during inspection:
  • Remove the faulty ignition coil as previously stated.
  • Install the new ignition coil in place of the old one.
  • Reconnect the electrical connector.

4. Clean or Replace Fuel Injector (if necessary)

• If the fuel injector is clogged:
  • Remove the fuel injector from cylinder 1:
    • Disconnect the fuel line carefully (use a cloth to catch any spills).
    • Unplug the electrical connector.
    • Unscrew the injector retaining clips and pull out the injector.
  • Clean the injector using a fuel injector cleaner or replace it with a new one.
• Reinstall the fuel injector, ensuring proper seating and securing clips.

5. Restore Electrical Connections

• Inspect and repair any damaged wiring or connectors associated with the ignition coil and fuel injector.
• Ensure all connections are secure and free from corrosion.

Tools Required:

• OBD-II scanner
• Socket set (including spark plug socket)
• Torque wrench
• Fuel line disconnect tool
• Multimeter (for electrical testing)
• Compression tester

Parts Required:

• Spark plug (specific to vehicle specifications)
• Ignition coil (if faulty)
• Fuel injector (if needed)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow engine to cool before opening any components.