why is my BMW 3 Series G20/G21 (2019-2024) check engine light blinking?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.
• Allow the engine to cool if it has been running.

2. Addressing Ignition System Issues

• Inspect Spark Plugs:

  • Remove the spark plug wires and use a socket to remove the spark plugs.
  • Check for wear or damage (e.g., carbon buildup, cracked insulator).
  • Replace with new, manufacturer-recommended spark plugs if necessary.

• Check Ignition Coils:

  • Visually inspect the ignition coils for cracks or corrosion.
  • Use a multimeter to test resistance (consult specifications for correct values).
  • Replace any faulty coils.

3. Vacuum Leak Repair

• Inspect Hoses:
  • Visually inspect all vacuum hoses for cracks or disconnections.
  • Use a smoke machine or carburetor cleaner to identify leaks.
  • Replace any damaged hoses.

4. Fuel System Check

• Test Fuel Pressure:
  • Connect a fuel pressure gauge to the fuel rail.
  • Turn the ignition on (do not start the engine) to check for proper pressure.
  • If pressure is low, check the fuel pump, filter, and relay for issues.
  • Replace the fuel filter if it has not been changed recently.

5. Exhaust System Inspection

• Check for Blockages:
  • Inspect the exhaust system visually for dents or rust.
  • Use a backpressure gauge to test for exhaust restrictions.
  • Replace any damaged components or clear blockages.