my BMW 5 Series G30/G31 (2017-2024) has a code P0301, how do I fix it?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical shorts.
• Allow the engine to cool before working on any components.

2. Inspect and Replace Ignition Components

1. Remove Engine Cover (if applicable)
   • Use a socket set to remove any bolts holding the cover in place.
2. Remove Spark Plug
   • Use a spark plug socket and ratchet to carefully remove the spark plug from cylinder 1.
   • Inspect the spark plug for signs of wear, carbon buildup, or damage.
3. Replace Spark Plug (if necessary)
   • Install a new spark plug, ensuring it is gapped correctly (typically 0.032-0.036 inches for most BMWs).
   • Torque the spark plug to the manufacturer’s specifications (usually around 15-20 ft-lbs).
4. Remove Ignition Coil
   • Disconnect the electrical connector from the ignition coil.
   • Remove the retaining screws and lift the ignition coil out.
5. Replace Ignition Coil (if necessary)
   • Install a new ignition coil for cylinder 1 and secure it with screws.
   • Reconnect the electrical connector.

3. Inspect and Replace Fuel Injector

1. Remove Fuel Rail (if necessary)
   • Release fuel pressure by removing the fuel pump fuse and running the engine until it stalls.
   • Disconnect fuel lines and remove any retaining bolts for the fuel rail.
2. Replace Fuel Injector
   • Remove the fuel injector from cylinder 1 by pulling it from the fuel rail.
   • Install a new fuel injector, ensuring it is seated properly in the intake manifold.
3. Reinstall Fuel Rail (if removed)
   • Reattach the fuel rail and secure it with bolts, reconnecting any fuel lines and electrical connections.

4. Reassemble and Test

1. Reattach Engine Cover (if removed)
   • Secure the engine cover back into place.
2. Reconnect Battery
   • Reconnect the battery terminals and ensure they are tight.
3. Clear Error Codes
   • Use an OBD-II scanner to clear the P0301 code and any other stored codes.
4. Test Drive the Vehicle
   • Start the engine and take the vehicle for a test drive to ensure the misfire issue is resolved.