what does it mean if my BMW 3 Series F30/F31 (2012-2019) has a P0302 code

Solution

1. Preparation

• Gather tools and parts for the repair.
• Disconnect the battery to ensure safety during the process.
• Allow the engine to cool down before working on it.

2. Inspect and Replace Spark Plug and Ignition Coil

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector for cylinder 2.
• Remove the ignition coil using a socket.
• Remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear; replace it with a new one if necessary (Torque to manufacturer specifications, typically around 15 ft-lbs).
• Install the new ignition coil and reconnect the connector.

3. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector removal tool, socket set.
• Relieve the fuel system pressure by removing the fuel pump fuse and running the engine until it stalls.
• Disconnect the battery again for safety.
• Remove the fuel rail bolts and gently lift the rail to access the injectors.
• Disconnect the connector from the injector for cylinder 2.
• Remove the fuel injector and replace it with a new one.
• Reassemble the fuel rail and reconnect all connectors.

4. Compression Test (if needed)

• Tools Required: Compression tester.
• Remove the spark plug for cylinder 2.
• Install the compression tester and crank the engine.
• Record the compression reading; it should match the manufacturer’s specifications (typically around 150 psi).
• If compression is low, further diagnostic steps are needed to assess potential internal engine issues.