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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Remove any necessary engine covers for access to the ignition system.

2. Inspect and Replace Spark Plug

• Remove the spark plug from cylinder 1 using a spark plug socket.
• Inspect the spark plug for signs of wear or fouling (carbon buildup, oil, or excessive wear).
• If damaged, replace with a new spark plug of the recommended type (typically NGK or Bosch).
• Torque the new spark plug to the manufacturer’s specifications (generally around 20 Nm).

3. Check and Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil for cylinder 1.
• Remove the ignition coil by unscrewing any retaining bolts and pulling straight up.
• Inspect the coil for cracks or burn marks. If defective, replace it with a new OEM ignition coil.
• Reinstall the new ignition coil and reconnect the electrical connector securely.

4. Inspect and Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a noid light to check for proper electrical signal to the injector. If there's no signal, further diagnostics are required for the engine control module.
• If the injector is suspected to be faulty, remove it and clean or replace it.
• Reinstall the fuel injector and reconnect the electrical connector.

5. Compression Test (if necessary)

• Remove the spark plug from cylinder 1 and install the compression tester in its place.
• Crank the engine and record the compression reading. It should be within the manufacturer’s specified range (typically around 160-200 psi).
• If compression is low, further investigation into the piston rings, valves, or head gasket may be needed.