my BMW 5 Series G30/G31 (2017-2024) has a rough start and dies, what are the causes?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface with the engine off.
• Disconnect the battery to prevent electrical shocks.

2. Inspect and Replace Battery (if necessary)

• Sub-steps:
  1. Remove the battery terminals, starting with the negative terminal.
  2. Check the battery voltage with a multimeter; replace battery if voltage is below 12.4V.
  3. Clean battery terminals and cable connections.
  4. Reconnect the battery terminals, ensuring a secure fit.
• Tools Required: Multimeter, socket set for battery terminals.

3. Fuel System Inspection

• Sub-steps:
  1. Remove the fuel pump fuse and crank the engine to relieve fuel pressure.
  2. Disconnect the fuel line at the fuel rail and attach a fuel pressure gauge.
  3. Turn the ignition to the 'ON' position (do not start) and check for proper fuel pressure (should be within manufacturer specifications).
  4. If pressure is low, replace the fuel pump.
  5. Reconnect the fuel line and replace the fuse.
• Tools Required: Fuel pressure gauge, socket set.

4. Air Intake System Check

• Sub-steps:
  1. Inspect the air filter for clogging and replace if dirty.
  2. Check for any cracks or leaks in the intake hoses.
  3. Clean the mass air flow (MAF) sensor using MAF cleaner.
• Tools Required: Screwdriver set, MAF cleaner.

5. Ignition System Check

• Sub-steps:
  1. Remove spark plugs and inspect for wear or fouling.
  2. Test each ignition coil using a multimeter for proper resistance.
  3. Replace any faulty spark plugs or ignition coils.
• Tools Required: Socket set, multimeter.