how to resolve the P0301 code on my BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before starting any work.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 using a socket set.
• Extract the spark plug using a spark plug socket.
• Inspect the spark plug for wear, deposits, or damage; replace if necessary.
• Install a new spark plug (recommended gap: check manufacturer specifications).
• Reinstall the ignition coil securely.

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil using an ohmmeter.
• If the coil is faulty, disconnect the wiring harness and remove the ignition coil.
• Install the new ignition coil and reconnect the wiring harness.

4. Fuel Injector Testing

• If misfire persists, check the fuel injector for cylinder 1.
• Remove the fuel injector connector and fuel rail bolts.
• Carefully extract the fuel injector.
• Inspect for clogs or carbon buildup; clean or replace as necessary.
• Reinstall the injector and reconnect the fuel rail.

5. Compression Test

• If previous steps do not resolve the issue, perform a compression test on cylinder 1.
• Remove the spark plug and attach a compression gauge.
• Crank the engine and record the reading; compare with manufacturer specifications.
• If the compression is low, further engine diagnostics may be required.