how to fix P0302 code on BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket, pliers.
• Remove the engine cover if necessary.
• Disconnect the electrical connector from the ignition coil on cylinder 2.
• Remove the ignition coil using the socket set.
• Inspect the ignition coil for cracks or carbon tracking. Replace if necessary.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear or fouling. Replace if necessary.
• Install the new spark plug and torque to manufacturer specifications (typically 22 Nm).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect Fuel Injector

• Tools Required: Noid light or multimeter, fuel injector cleaner (if necessary).
• Disconnect the fuel injector connector for cylinder 2.
• Test the injector with a noid light to verify it is receiving a signal. Replace if it does not light up.
• If the injector is functioning, clean it using fuel injector cleaner or replace it if clogged.

4. Check for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• With the engine running, use a smoke machine to check for leaks around the intake manifold.
• Alternatively, spray carburetor cleaner near suspected areas and listen for changes in engine RPM.
• Repair any identified vacuum leaks.

5. Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 2.
• Insert the compression tester into the spark plug hole.
• Crank the engine and record the compression reading. Compare against manufacturer specifications.
• If compression is low, further investigation may be needed for internal engine issues.