how to fix P0302 misfire code in BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before working on any components.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Unplug the ignition coil connector for cylinder 2.
  3. Remove the ignition coil using a socket wrench.
  4. Remove the old spark plug using a spark plug socket.
  5. Inspect and clean the spark plug hole.
  6. Install the new spark plug (torque to 23 Nm).
  7. Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. Swap the ignition coil from cylinder 2 with another cylinder.
  2. Clear the trouble codes with the OBD-II scanner.
  3. Start the engine and check for the misfire code again.
  4. If the misfire follows the ignition coil, replace the ignition coil for cylinder 2.
  5. Reinstall the ignition coil and reconnect the electrical connector.

4. Inspect and Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Remove the intake manifold if required to access the fuel injector.
  2. Disconnect the fuel injector electrical connector.
  3. Remove the fuel rail bolts and gently pull the fuel rail off the injectors.
  4. Remove the fuel injector from cylinder 2 (may require a special tool).
  5. Install the new fuel injector and ensure proper seating.
  6. Reassemble the fuel rail and intake manifold; reconnect all electrical connectors.

Tools Required:

• OBD-II scanner
• Socket set (including spark plug socket)
• Torque wrench
• Compression tester
• Fuel injector removal tool (if needed)

Parts Required:

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

Estimated Repair Time: 2-4 hours

Safety Warnings:

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