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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the engine off and cool.
• Disconnect the battery to avoid electrical shorts.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, dielectric grease.
• Remove the engine cover (if applicable).
• Disconnect the ignition coil connector from cylinder 1.
• Remove the ignition coil using a socket wrench.
• Remove the spark plug using a spark plug socket, inspecting it for wear or damage.
• Install the new spark plug, ensuring it is gapped correctly (consult specifications).
• Reinstall the ignition coil and reconnect the connector.
• Apply dielectric grease to the coil boot.

3. Test or Replace Ignition Coil

• If the ignition coil was tested and found faulty:
  • Remove the faulty coil as described above.
  • Install a new ignition coil, ensuring a secure connection.
• If the ignition coil is functioning, proceed to the next step.

4. Inspect and Clean Fuel Injector

• Tools Required: Fuel injector cleaning kit (if necessary).
• Disconnect the fuel line and electrical connector from the fuel injector for cylinder 1.
• Remove the fuel injector from the rail.
• Clean or replace the injector as necessary.
• Reinstall the fuel injector and reconnect the fuel line and electrical connector.

5. Compression Test

• Tools Required: Compression tester.
• Remove the spark plug for cylinder 1.
• Screw the compression tester into the spark plug hole.
• Crank the engine and observe the compression reading; compare with specifications.
• If compression is low, further diagnosis may be needed (valve issues, gasket leaks).