how do I deal with a P0301 code in my BMW 5 Series G30/G31 (2017-2024)?

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.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Sub-steps:
  1. Remove the engine cover (if applicable) by unscrewing the retaining bolts.
  2. Disconnect the ignition coil connector for cylinder 1.
  3. Remove the ignition coil by unscrewing the retention bolts.
  4. Using a spark plug socket, remove the old spark plug.
  5. Install the new spark plug by hand to avoid cross-threading, then torque it to the manufacturer's specifications (typically around 15-25 Nm).
  6. Reinstall the ignition coil and reconnect the connector.

3. Test Ignition Coil

• Tools Required: Multimeter.
• Sub-steps:
  1. Disconnect the ignition coil connector and remove the coil.
  2. Use a multimeter to check the primary and secondary resistance of the coil against manufacturer specifications (usually 0.5-2.0 ohms for primary, 6-15 k ohms for secondary).
  3. Replace the ignition coil if it does not meet specifications.

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaner or replacement injector, fuel line disconnect tool.
• Sub-steps:
  1. Disconnect the fuel line from the fuel injector (ensure the fuel pressure is relieved).
  2. Remove the fuel injector retaining clips and the injector itself.
  3. Clean the injector using an appropriate cleaning solution or replace it if necessary.
  4. Reinstall the injector with new O-rings and clips.

5. Reassemble and Reconnect Battery

• Reinstall any components removed during the process.
• Reconnect the negative battery terminal.
• Start the engine and check for proper operation.