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

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, compression tester, noid light, multimeter, fuel pressure gauge.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool before beginning work.

2. Inspect and Replace Ignition Coil

1. Remove Engine Cover:

   • Use a socket set to remove any bolts securing the engine cover and lift it off carefully.

2. Remove Ignition Coil:

   • Disconnect the electrical connector from the ignition coil on cylinder 1.
   • Remove the retaining bolt(s) and pull the ignition coil straight out.

3. Install New Ignition Coil:

   • Insert the new ignition coil into the cylinder and secure it with the retaining bolt(s).
   • Reconnect the electrical connector.

3. Inspect and Replace Spark Plug

1. Remove Spark Plug:

   • Use a spark plug socket and ratchet to remove the spark plug from cylinder 1.
   • Inspect the spark plug for wear, carbon buildup, or damage.

2. Install New Spark Plug:

   • Gap the new spark plug to manufacturer specifications.
   • Insert the new spark plug and torque it to the manufacturer's specifications (typically around 18-25 Nm).

3. Reattach Engine Cover:

   • Place the engine cover back on and secure it with the bolts.

4. Inspect and Replace Fuel Injector (if necessary)

1. Remove Fuel Rail:

   • Relieve fuel pressure, then disconnect the fuel lines and wiring from the fuel rail.
   • Remove the bolts securing the fuel rail and carefully lift it off.

2. Replace Fuel Injector:

   • Remove the old injector from the rail and install the new injector, ensuring it seats correctly.

3. Reassemble Fuel Rail:

   • Reattach the fuel rail to the engine, securing with bolts and reconnecting fuel lines.