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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent any electrical shorts.
• Ensure the engine is cool before beginning work.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil from cylinder 2 by unscrewing any retaining bolts and gently pulling it out.
  2. Unscrew the spark plug from cylinder 2 using a spark plug socket.
  3. Install the new spark plug into cylinder 2 and torque it to the manufacturer's specification (typically around 18-22 lb-ft).
  4. Reinstall the ignition coil and secure it with the retaining bolts.

3. Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If the ignition coil is found to be faulty during testing, remove it from the engine by unscrewing the retaining bolts.
  2. Disconnect the electrical connector from the ignition coil.
  3. Install the new ignition coil by reconnecting the electrical connector and securing it with bolts.

4. Clean or Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Disconnect the fuel rail and remove the injector from cylinder 2.
  2. If cleaning, use an appropriate fuel injector cleaner and follow the manufacturer's instructions. If replacing, install the new injector.
  3. Reassemble the fuel rail ensuring all connections are secure.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0302 code from the system.