what causes the P0302 code on my BMW 5 Series F10/F11 (2010-2017) and how to fix it

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil cover by unscrewing any retaining bolts.
• Disconnect the electrical connector from the ignition coil in cylinder 2.
• Remove the ignition coil and inspect it for cracks or damage.
• Using a spark plug socket, remove the spark plug from cylinder 2.
• Install the new spark plug and torque to manufacturer specifications (typically 18 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test/Replace Ignition Coil

• If the ignition coil appears faulty (cracked or burnt), replace it with a new one.
• Ensure it is seated correctly and reconnect any electrical connections.

4. Inspect/Replace Fuel Injector

• Tools Required: Fuel injector removal tool, O-ring lubricant.
• Remove the fuel rail if necessary to access the injector in cylinder 2.
• Disconnect the electrical connector from the fuel injector.
• Remove the injector and inspect it for clogs or damage.
• If faulty, replace the injector and lubricate O-rings before installation.
• Reinstall the fuel rail and reconnect all electrical connectors.

5. Verify Compression

• If misfire persists after replacing spark plugs and ignition coil, perform a compression test on cylinder 2.
• If compression is low, further engine repairs may be necessary (e.g., valve issues, piston rings).