how to fix the P0302 code in my BMW 3 Series E90/E91 (2005-2012)?

Solution

1. Preparation

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

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench
• Remove the ignition coil from cylinder 2 by unscrewing the retaining bolt and gently pulling it out.
• Using a spark plug socket, remove the old spark plug from cylinder 2.
• Inspect the spark plug threads and clean if necessary.
• Install the new spark plug, tightening it to the manufacturer’s specified torque (typically around 15-20 lb-ft).
• Reinstall the ignition coil and secure it with the retaining bolt.

3. Replace Ignition Coil

• Tools Required: Ratchet set, torque wrench
• If after inspection the ignition coil is faulty, remove it as described above.
• Install the new ignition coil in cylinder 2, ensuring it is seated properly.
• Tighten the retaining bolt to the specified torque (usually around 10-12 lb-ft).

4. Check Fuel Injector

• Tools Required: Fuel injector puller (if necessary), cleaning solvent
• Disconnect the electrical connector from the fuel injector for cylinder 2.
• If blockage is suspected, remove the fuel injector by unscrewing it from the rail.
• Clean the injector with appropriate solvent or replace with a new injector.
• Reinstall the injector and reconnect the electrical connector.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0302 code and any other stored codes in the system.