how to fix P0301 code in BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety while working on electrical components.
• Allow the engine to cool down before starting any repairs.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1:

  • Unplug the electrical connector from the ignition coil.
  • Remove the retaining bolt using a socket set.
  • Carefully pull the ignition coil out of the spark plug well.

• Inspect the spark plug:

  • Remove the spark plug using a spark plug socket.
  • Check for signs of wear, fouling, or damage.
  • If necessary, replace the spark plug with a new one (specify OEM part).

• Reinstall the new spark plug:

  • Torque the spark plug to the manufacturer's specification (usually around 23 Nm).
  • Reinstall the ignition coil and secure it with the retaining bolt.

3. Check and Replace Ignition Coil

• If the spark plug is in good condition but the misfire persists, test the ignition coil:

  • Swap the ignition coil from cylinder 1 with another cylinder (e.g., cylinder 2).
  • Clear the codes and run the engine to see if the P0301 code moves to the new cylinder.

• If it does, replace the ignition coil for cylinder 1.

  • Follow the same removal and installation procedure as above.

4. Inspect and Replace Fuel Injector

• If the ignition components are functioning correctly, test the fuel injector for cylinder 1:

  • Use a multimeter to test the resistance of the fuel injector.
  • If faulty, remove the fuel injector:
    • Disconnect the electrical connector.
    • Remove the fuel rail, taking care to relieve fuel pressure first.

• Install the new fuel injector:

  • Lubricate the O-ring of the new injector with engine oil.
  • Insert it into the fuel rail and reassemble the components.

5. Final Steps

• Reconnect the battery terminal.
• Clear the codes using an OBD-II scanner.
• Start the engine and monitor for any misfire codes.