why does my BMW X3 F25 (2011-2018) have a check engine light with P0302 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 2:
  1. Disconnect the electrical connector from the ignition coil.
  2. Remove the bolts securing the ignition coil and lift it out.
• Remove the spark plug:
  1. Use a spark plug socket to unscrew the spark plug from the cylinder head.
• Install the new spark plug:
  1. Apply anti-seize lubricant on the threads of the new spark plug.
  2. Hand-tighten the spark plug and then torque it to the manufacturer’s specification (typically around 20 Nm).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil (if necessary)

• If the ignition coil was found faulty during diagnostics:
  1. Follow the same steps as above to remove the faulty ignition coil.
  2. Install the new ignition coil by reversing the removal steps.

4. Inspect and Replace Fuel Injector (if necessary)

• If the fuel injector is not functioning:
  1. Remove the fuel rail to access the injector.
  2. Disconnect the electrical connector and fuel line from the injector.
  3. Remove the injector from the rail and install a new injector, ensuring proper sealing and alignment.

5. Test and Reassemble

• Reconnect the fuel line, ignition coils, and any electrical connections that were disconnected.
• Reconnect the negative battery terminal.