my BMW 5 Series F10/F11 (2010-2017) shows a P0301 code, what should I check?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Replace Spark Plug

• Remove the engine cover if applicable.
• Using a spark plug socket, remove the spark plug from cylinder 1.
• Inspect the spark plug for fouling or wear; replace with a new spark plug if necessary.
• Torque the new spark plug to the manufacturer’s specification (usually around 18-21 lb-ft).

3. Inspect and Replace Ignition Coil

• Disconnect the ignition coil connector from cylinder 1.
• Remove the ignition coil using a socket or ratchet.
• Visually inspect the coil for cracks or damage; replace it if any issues are found.
• Install the new ignition coil, ensuring it is seated properly, and reconnect the connector.

4. Check and Clean Fuel Injector

• Disconnect the fuel injector connector from cylinder 1.
• Remove the fuel rail to access the injector, taking care of any fuel spills.
• Inspect the injector for clogs or leaks; clean or replace as necessary.
• Reinstall the fuel injector and reconnect the fuel rail.

5. Compression Test (if needed)

• If misfire persists, perform a compression test on cylinder 1.
• Remove the spark plug and insert the compression tester into the cylinder.
• Crank the engine and read the compression value; compare it to specifications.
• If compression is low, further diagnostics may be necessary for internal engine issues.