how to fix P0171 code in Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before beginning.

2. Inspect and Repair Air Intake

• Sub-steps:
  1. Remove the air intake duct by loosening the clamps and disconnecting any sensors attached.
  2. Inspect for cracks or damage in the duct and replace if necessary.
  3. Check the air filter and replace it if it is clogged or dirty.
  4. Reinstall the air intake duct securely.

3. Clean or Replace MAF Sensor

• Tools Required: MAF cleaner or isopropyl alcohol, soft cloth
• Sub-steps:
  1. Carefully disconnect the MAF sensor connector.
  2. Remove the MAF sensor from the air intake.
  3. Clean the sensor element with MAF cleaner; do not touch it with your fingers.
  4. Allow it to dry completely before reinstalling.

4. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail access port.
  2. Turn the ignition to the “ON” position without starting the engine to check the fuel pressure.
  3. Compare the reading to the manufacturer’s specifications.
  4. If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for issues.
  5. Replace any faulty parts as necessary.

5. Inspect Vacuum Lines

• Sub-steps:
  1. Visually inspect all vacuum lines for cracks, breaks, or loose connections.
  2. Use a smoke machine or apply a small amount of carb cleaner around the vacuum lines while the engine is running to detect leaks (the engine will change RPM if a leak is present).
  3. Repair or replace any damaged vacuum lines.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Clear the P0171 code using the OBD-II scanner.
• Start the engine and allow it to idle.