how to fix P0301 misfire code on my BMW X5 F15 (2014-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Replace Spark Plug

• Remove the engine cover if necessary.
• Locate cylinder 1 spark plug (refer to the vehicle’s service manual for precise location).
• Using a spark plug socket and ratchet, carefully remove the old spark plug.
• Inspect the spark plug gap and condition; clean any debris from the cylinder head.
• Install the new spark plug, ensuring the gap is set to manufacturer specifications (usually around 0.028-0.032 inches for BMW).
• Torque the spark plug to the manufacturer’s specified value (typically around 15-20 Nm).

3. Inspect/Replace Ignition Coil

• If the spark plug replacement does not resolve the issue, proceed to the ignition coil.
• Remove the ignition coil for cylinder 1 by disconnecting the electrical connector and removing the mounting bolts.
• If swapping the ignition coil in step 3 of diagnostics indicated a faulty coil, replace it with a new one.
• Ensure the new coil is seated properly and reconnect the electrical connector.

4. Check/Replace Fuel Injector

• If misfire persists, inspect the fuel injector for cylinder 1.
• Remove the fuel rail if necessary to access the fuel injector.
• Test the injector using a noid light to check for proper signal.
• If the injector is found to be faulty, replace it with a new injector, ensuring proper seating and connection.

5. Reassemble and Reconnect

• Reinstall any components removed during the procedure, including the engine cover.
• Reconnect the vehicle's battery.