my BMW 3 Series F30/F31 (2012-2019) has a blinking check engine light, what should I do?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, and basic hand tools.
• Safety Warnings: Disconnect the battery before starting any electrical work to avoid shorts.

2. Diagnose and Replace Spark Plugs

1. Remove Engine Cover:

   • Unscrew any fasteners holding the engine cover in place.
   • Carefully lift the cover off and set it aside.

2. Access Spark Plugs:

   • Detach ignition coil connectors by pressing the release tab and pulling them off.
   • Remove the bolts securing the ignition coils and carefully pull them out.

3. Inspect and Replace Spark Plugs:

   • Use a spark plug socket to remove old spark plugs.
   • Inspect the spark plugs for signs of wear, carbon buildup, or damage.
   • Install new spark plugs, ensuring to torque them to the manufacturer’s specification (typically around 15 ft-lbs for BMW).

3. Check and Replace Ignition Coils (if necessary)

1. Testing Ignition Coils:

   • Use a multimeter to test the resistance of each ignition coil based on manufacturer specifications.

2. Replace Faulty Coils:

   • If any coils are out of specs, replace them with new units.
   • Reinstall the ignition coils and connectors.

4. Inspect Fuel Injectors

1. Check Injector Operation:

   • Use a fuel pressure gauge to ensure proper fuel pressure.
   • If fuel pressure is low, inspect the fuel filter and pump.

2. Clean or Replace Injectors:

   • If injectors are clogged, either clean them using a professional cleaning kit or replace them as needed.

5. Inspect Vacuum Lines

1. Visual Inspection:

   • Check for any visible cracks or damage in the vacuum lines.

2. Replace Damaged Lines:

   • Cut and replace any damaged vacuum lines with new hoses.