my Volkswagen Passat B8 (2015-2022) check engine light is flashing, what should I do?

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative terminal of the battery to prevent electrical shocks.
• Gather necessary tools and parts.

2. Addressing Ignition Issues

• Tools Required: Socket set, torque wrench, spark plug socket.
• Sub-steps:
  1. Remove engine cover if applicable.
  2. Remove spark plug wires or coils carefully.
  3. Use a spark plug socket to remove each spark plug; inspect for wear or damage.
  4. Replace any defective spark plugs with OEM equivalents.
  5. Reinstall spark plugs and torque them to the manufacturer's specifications (usually around 15-20 Nm).
  6. Reconnect spark plug wires or coils securely.

3. Inspecting Fuel Injectors

• Tools Required: Fuel pressure gauge, injector cleaner.
• Sub-steps:
  1. Relieve fuel system pressure by removing the fuel pump relay and starting the engine until it stalls.
  2. Disconnect the fuel injector connectors and remove the fuel rail.
  3. Inspect fuel injectors for clogs; use an injector cleaner if necessary.
  4. Reinstall the fuel rail and injectors, ensuring proper sealing and connection.
  5. Reconnect the fuel pump relay.

4. Checking for Vacuum Leaks

• Tools Required: Smoke machine or carburetor cleaner.
• Sub-steps:
  1. Inspect all vacuum hoses visually for cracks or disconnections.
  2. Use a smoke machine to introduce smoke into the intake system; observe for smoke escaping, indicating leaks.
  3. Replace any damaged vacuum hoses and seal leaks.