my BMW 5 Series F10/F11 (2010-2017) has a check engine light with code P0301, what now?

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. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil for cylinder 1 by unscrewing the mounting bolts.
• Disconnect the electrical connector from the ignition coil.
• Remove the old spark plug using the spark plug socket.
• Install the new spark plug, torquing it to the manufacturer’s specifications (typically 22 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• If the ignition coil shows signs of damage or malfunction during inspection:
  • Tools Required: Socket set, torque wrench
  • Remove the mounting bolts from the ignition coil and lift it out.
  • Install the new ignition coil, securing it with the original bolts, and reconnect the electrical connector.

4. Fuel Injector Inspection/Replacement (if necessary)

• If the fuel injector is suspected to be clogged:
  • Tools Required: Fuel injector cleaning kit or replacement injector
  • Disconnect the fuel line and electrical connector from the injector.
  • Remove the injector from the rail.
  • Clean or replace the injector, ensuring all seals are replaced.
  • Reinstall and reconnect the fuel line and electrical connector.

5. Reconnect Battery

• Reconnect the negative battery terminal securely.