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

Solution

1. Preparation

• Gather all necessary tools and parts before starting the repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug in Cylinder 2

• Remove the engine cover to access the spark plugs.
• Use a socket wrench to remove the spark plug from cylinder 2.
• Inspect the old spark plug for signs of wear such as carbon build-up or damage.
• Install the new spark plug, tightening it to the manufacturer's specified torque (typically around 15 ft-lbs).
• Reattach the engine cover and reconnect the battery.

3. Inspect and Replace Ignition Coil (if necessary)

• Remove the ignition coil from cylinder 2 by unscrewing it and disconnecting the electrical connector.
• If the coil shows signs of damage or is not functional, replace it with a new one.
• Reinstall the ignition coil, ensuring it is seated properly and the connector is secure.

4. Test Fuel Injector

• Locate the fuel injector for cylinder 2 and disconnect the electrical connector.
• Use a multimeter to check for proper resistance (usually around 12-16 ohms).
• If the injector is faulty, replace it with a new one.
• Reconnect the electrical connector and ensure it is secure.

5. Check for Vacuum Leaks

• Visually inspect all vacuum hoses connected to the intake manifold and replace any that are cracked or disconnected.
• Perform a smoke test if necessary to identify any hidden leaks.