what causes the check engine light to come on in my BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts during repairs.

2. Retrieve and Analyze Codes

• Use an OBD-II scanner to check for stored fault codes.
• Document any codes and research their meanings to identify potential issues.

3. Address Faulty Components

• Air Intake System:
  • Inspect the air filter for dirt and replace if necessary.
  • Check for cracks or loose connections in the intake hoses.
• Fuel System:
  • Replace clogged fuel filters if applicable.
  • Test fuel pressure with a fuel pressure gauge and replace the fuel pump if pressure is low.
• Ignition System:
  • Replace worn spark plugs and ignition coils if misfire codes are present.
• Exhaust System:
  • Inspect for leaks or damage; replace components as needed.

4. Clear Codes and Test Drive

• After repairs, use the OBD-II scanner to clear the fault codes.
• Reconnect the battery and start the engine.
• Monitor the engine's performance during a test drive to ensure the CEL does not re-illuminate.