how to fix P0302 code in BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaning kit.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug

• Remove the ignition coil for cylinder 2 by unscrewing the mounting bolts.
• Pull the ignition coil out gently.
• Remove the spark plug using a spark plug socket.
• Inspect the old spark plug for signs of wear or damage.
• Install a new spark plug, torquing it to the manufacturer’s specification (usually around 22 lb-ft for BMW).
• Reinstall the ignition coil and secure it in place.

3. Test or Replace Ignition Coil

• Use a multimeter to check the resistance of the ignition coil for cylinder 2. Compare readings with manufacturer specifications.
• If the coil is faulty, replace it with a new one, ensuring it is securely connected.

4. Check Fuel Injector

• Remove the fuel rail if necessary to access the injector for cylinder 2.
• Inspect the injector for clogs or leaks.
• If cleaning does not resolve the issue, replace the fuel injector with a new one.
• Reinstall the fuel rail and ensure all connections are tight.

5. Perform Compression Test

• Insert the compression tester into the spark plug hole for cylinder 2.
• Crank the engine and record the compression reading.
• Compare the result with manufacturer specifications (usually around 120-200 psi for BMW).
• If compression is low, further engine diagnosis may be required for potential internal issues.