how to diagnose P0174 code in Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts. Ensure the vehicle is parked on a flat surface and the engine is off.
• Tools required: OBD-II scanner, fuel pressure gauge, multimeter, MAF cleaner, socket set, torque wrench.
• Safety warning: Disconnect the battery before working on electrical systems.

2. Inspect Air Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses and connections for signs of wear or damage.
  2. Tighten any loose clamps and replace damaged hoses.
  3. Remove the air filter and inspect it for dirt or clogging; replace if necessary.

3. Check Fuel System Pressure

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail Schrader valve.
  2. Turn the ignition to the “ON” position (do not start the engine) and check the pressure reading.
  3. Compare the reading to manufacturer specifications (typically between 50-60 psi for most models); if low, inspect the fuel pump and filter.

4. Inspect MAF Sensor

• Sub-steps:
  1. Disconnect the electrical connector from the MAF sensor.
  2. Remove the MAF sensor from the air intake tube.
  3. Clean the sensor with MAF cleaner and allow it to dry before reinstallation.

5. Check Vacuum Lines

• Sub-steps:
  1. Inspect all vacuum lines connected to the intake manifold for cracks or loose connections.
  2. Replace any damaged lines and ensure all connections are secure.

6. Inspect Fuel Injectors

• Sub-steps:
  1. Use a multimeter to check the resistance of each injector (should be within the specified range).
  2. Use a noid light to verify that the injector is receiving the correct pulse signal from the ECM.
  3. Replace any faulty injectors as needed.