how to fix P0301 code in BMW 3 Series G20/G21 (2019-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is off and cool.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Sub-steps:
  1. Disconnect the negative battery terminal to prevent electrical shock.
  2. Remove the ignition coil from cylinder 1 by unscrewing bolts and gently pulling it out.
  3. Remove the old spark plug using the spark plug socket.
  4. Inspect the spark plug for wear; if necessary, replace it with a new one, ensuring the gap is set according to manufacturer specifications (typically around 0.032 inches).
  5. Torque the new spark plug to the manufacturer’s specified value (usually around 16 ft-lbs).

3. Replace Ignition Coil (if needed)

• Tools Required: Socket set, torque wrench.
• Sub-steps:
  1. If the ignition coil is damaged, replace it with a new unit.
  2. Install the new ignition coil onto the spark plug and secure it with bolts.
  3. Reconnect the electrical connector to the ignition coil.

4. Test Fuel Injector

• Tools Required: Noid light or multimeter.
• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Test the injector's electrical signal with a noid light to ensure proper functionality.
  3. If the injector does not function, replace it with a new one, ensuring proper seating and connection.

5. Final Checks

• Reconnect the negative battery terminal.
• Clear the codes using an OBD-II scanner.
• Start the engine and observe for any signs of misfire or check engine light activation.