my Volkswagen Passat B8 (2015-2022) stalls at low speed what could it be

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the battery to ensure safety while working on electrical components.
• Allow the engine to cool if it has been running.

2. Fuel System Inspection

• Tools Required: Fuel pressure gauge, socket set.
• Steps:
  1. Locate the fuel rail and connect the fuel pressure gauge.
  2. Turn the ignition to the "ON" position (without starting the engine) and check the fuel pressure.
  3. Compare the reading with the manufacturer's specifications (usually around 50-60 psi).
  4. If the pressure is low, replace the fuel filter and check the fuel pump operation.

3. Ignition System Repair

• Tools Required: Spark plug socket, torque wrench.
• Steps:
  1. Remove the engine cover (if applicable) and access the ignition components.
  2. Inspect and replace spark plugs if they are worn or fouled (typically torque to 25 Nm).
  3. Inspect ignition coils for cracks or damage; replace any faulty coils.
  4. Reconnect all components and the engine cover.

4. Mass Airflow Sensor (MAF) Cleaning/Replacement

• Tools Required: Torx screwdriver, MAF cleaner.
• Steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the MAF sensor from the duct.
  3. Clean the sensor with MAF cleaner; allow it to dry completely before reinstalling.
  4. If the sensor is damaged, replace it with a new one.

5. Idle Air Control (IAC) Valve Inspection

• Tools Required: Screwdriver set.
• Steps:
  1. Locate the IAC valve, usually near the throttle body.
  2. Disconnect the electrical connector and remove the valve.
  3. Clean the valve seat and the valve itself with intake cleaner.
  4. Reinstall the valve and reconnect the electrical connector.