what does it mean when my BMW 3 Series E90/E91 (2005-2012) gets a P0302 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety before working on electrical systems.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover (if applicable) to access the ignition components.
  2. Remove the spark plug from cylinder 2 using a spark plug socket.
  3. Inspect the spark plug for signs of wear or fouling. Replace with a new spark plug if necessary.
  4. Torque the new spark plug to the manufacturer’s specifications (usually around 20 Nm).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Disconnect the wiring harness from the ignition coil for cylinder 2.
  2. Remove the ignition coil using a socket or wrench (usually requires a T30 Torx).
  3. Inspect the coil for cracks or damage. Replace it with a new coil if it is faulty.
  4. Reinstall the new ignition coil and reconnect the wiring harness.

4. Check and Clean Fuel Injector

• Sub-steps:
  1. Remove the fuel rail (ensure fuel pressure is relieved prior to removal).
  2. Extract the fuel injector from cylinder 2.
  3. Clean the injector using a fuel injector cleaner or replace it if it's clogged or damaged.
  4. Reinstall the injector and the fuel rail, ensuring all seals are secure.

5. Reassemble and Reconnect Battery

• Sub-steps:
  1. Reinstall any components removed during the repair process.
  2. Reconnect the battery terminals.
  3. Clear the P0302 code from the ECM using an OBD-II scanner.