what does it mean when my BMW 5 Series G30/G31 (2017-2024) shows code P0301

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the engine cover if applicable.
• Unplug the ignition coil connector for cylinder 1.
• Remove the ignition coil using a socket.
• Inspect the spark plug and replace if necessary:
  • Remove the spark plug with a spark plug socket.
  • Check for signs of wear, such as carbon buildup or oil fouling.
  • Install a new spark plug, ensuring it is gapped correctly (check manufacturer specifications).
• Reinstall the ignition coil and connector securely.

3. Check and Clean Fuel Injector

• Tools Required: Fuel injector cleaner kit, safety glasses
• Disconnect the fuel injector connector for cylinder 1.
• Remove the fuel injector using a socket and inspect for clogs.
• Clean the fuel injector using a fuel injector cleaning kit or replace if damaged.
• Reinstall the fuel injector and reconnect the connector.

4. Perform Compression Test

• Tools Required: Compression tester
• Remove the ignition coil and spark plug for cylinder 1.
• Insert the compression tester into the spark plug hole.
• Crank the engine for a few seconds and record the compression reading.
• Compare the reading to the manufacturer's specification; if it's low, further investigation is needed.

5. Inspect for Vacuum Leaks

• Visually inspect vacuum hoses and gaskets around the intake manifold.
• Use a smoke machine or carburetor cleaner to check for leaks while the engine is running.
• Repair or replace any damaged hoses or gaskets found.