how to fix P0302 misfire code in my BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool completely before beginning work.

2. Replace Ignition Coil

1. Locate the ignition coil for cylinder 2 (refer to the engine layout).
2. Remove the electrical connector from the ignition coil.
3. Remove the mounting bolts securing the ignition coil.
4. Carefully pull the ignition coil out of the spark plug well.
5. Install the new ignition coil by reversing the removal steps.
   • Ensure it is seated properly.
   • Torque the bolts to the manufacturer's specifications (typically around 8-10 Nm).

3. Replace Spark Plug

1. Remove the ignition coil as described above.
2. Use a spark plug socket to remove the old spark plug from cylinder 2.
3. Inspect the spark plug for wear; replace if necessary.
4. Install the new spark plug, ensuring it is gapped correctly (usually around 0.7-0.8 mm for BMW).
5. Torque the spark plug to the manufacturer's specifications (typically around 25 Nm).
6. Reinstall the ignition coil.

4. Check and Clean Fuel Injector

1. Disconnect the fuel injector connector for cylinder 2.
2. Remove the fuel rail to access the injector.
3. Replace the fuel injector if it appears clogged or malfunctioning.
4. Reinstall the fuel rail and reconnect all connectors.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0302 code and any other stored codes.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Spark plug socket
• Screwdriver set

Parts Required:

• Ignition coil for cylinder 2
• Spark plug for cylinder 2
• Fuel injector (if necessary)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow the engine to cool before opening any components.