how to fix P0301 misfire code on BMW 5 Series G30/G31 (2017-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative terminal of the battery to prevent electrical shock.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if necessary to access the spark plugs.
  2. Use a spark plug socket and ratchet to carefully remove the spark plug from cylinder 1.
  3. Inspect the old spark plug for signs of wear or damage.
  4. Install a new spark plug (use OEM specifications) and torque to manufacturer specifications (usually around 22 lb-ft).

3. Replace Ignition Coil

• Sub-steps:
  1. Disconnect the electrical connector from the ignition coil in cylinder 1.
  2. Remove the ignition coil by unscrewing it from the cylinder head.
  3. Install the new ignition coil and secure it in place.
  4. Reconnect the electrical connector.

4. Inspect and Clean Fuel Injector

• Sub-steps:
  1. Remove the fuel rail to access the fuel injector for cylinder 1.
  2. Inspect the injector for clogs or damage.
  3. Clean the injector using a suitable fuel injector cleaner or replace if necessary.
  4. Reinstall the fuel rail and ensure proper sealing.

5. Address Compression Issues

• Sub-steps:
  1. If compression is low, it may indicate a deeper issue (e.g., valve problems, head gasket failure). Further diagnose as needed.
  2. If necessary, perform a leak-down test to pinpoint the problem.