how to solve P0302 code on my BMW X3 F25 (2011-2018)?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery before working on electrical components.
• Allow the engine to cool before starting the repair.

2. Spark Plug Replacement

• Tools Required: Socket set, torque wrench, dielectric grease.
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector from cylinder 2.
• Remove the ignition coil by unscrewing it from the engine.
• Extract the spark plug using a spark plug socket.
• Inspect the old spark plug for signs of wear, fouling, or damage.
• Install a new spark plug, ensuring it is gapped correctly to manufacturer specifications (typically around 0.032-0.036 inches).
• Torque the spark plug to the manufacturer’s specification (usually around 18-22 lb-ft).
• Apply dielectric grease to the ignition coil connector before reinstallation.
• Reinstall the ignition coil and reconnect the connector.

3. Ignition Coil Inspection and Replacement

• If the spark plug replacement does not resolve the issue, check the ignition coil operation.
• Swap the ignition coil from cylinder 2 with another cylinder (e.g., cylinder 1 or 3).
• Clear the P0302 code and run the engine to see if the misfire moves to the swapped cylinder.
• If it does, replace the faulty ignition coil with a new one.

4. Fuel Injector Inspection

• If the issue persists after replacing the ignition coil, inspect the fuel injector for cylinder 2.
• Check the electrical connection and wiring for any damage.
• If necessary, replace the fuel injector with a new one.

5. Compression Test (if needed)

• If all previous steps do not resolve the issue, perform a compression test on cylinder 2.
• If the compression is low, further investigation may be required to check for internal engine issues (such as a blown head gasket or valve problems).