my BMW 3 Series G20/G21 (2019-2024) is stalling while driving, what could be wrong?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts.

2. Addressing Fuel System Issues

• Check Fuel Pump:

  1. Locate the fuel pump fuse in the fuse box and inspect it for damage; replace if necessary.
  2. Use a fuel pressure gauge to check the fuel pressure at the rail; compare it with specifications for the G20/G21 model.
  3. If pressure is low, inspect the fuel pump and replace if it is faulty.

• Inspect Fuel Injectors:

  1. Remove the engine cover to access the fuel injectors.
  2. Check for clogged injectors; clean or replace them as necessary.

3. Inspecting Ignition System

• Check Spark Plugs and Coils:
  1. Remove spark plug wires and unscrew the spark plugs using a socket wrench.
  2. Inspect the spark plugs for wear or damage; replace if necessary.
  3. Test ignition coils with a multimeter for proper resistance; replace any faulty coils.

4. Electrical System Check

• Inspect Battery and Connections:
  1. Check the battery voltage with a multimeter; it should be around 12.6 volts when fully charged.
  2. Clean any corrosion from battery terminals and check for tight connections.
  3. If the battery is weak or failing, replace it with a new one.

5. Final Checks

• Reconnect the battery and start the engine.
• Perform a test drive to ensure the issue has been resolved.