Volkswagen Golf Seventh Generation (2013-2020) P0171 code, what are the common causes?

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks, tears, or disconnections.
  2. Use a smoke machine or propane torch (without igniting) to detect leaks in the intake system.
  3. Replace any damaged hoses or gaskets as necessary.

3. Clean or Replace the MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the intake duct.
  2. Disconnect the electrical connector.
  3. Remove the MAF sensor using the appropriate socket.
  4. Clean the sensor using MAF cleaner spray, or replace it if damaged.
  5. Reinstall the sensor and reconnect the electrical connector.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  1. Locate the fuel rail and connect the fuel pressure gauge.
  2. Turn the ignition to the "On" position without starting the engine to check the initial fuel pressure.
  3. Compare the reading to the manufacturer's specifications (usually around 50-60 psi for many models).
  4. If the pressure is low, check the fuel pump and fuel filter for issues.
  5. Replace the fuel filter if it’s clogged, or the fuel pump if it’s malfunctioning.

5. Inspect and Test Fuel Injectors

• Sub-steps:
  1. Disconnect the fuel injector connectors.
  2. Use a multimeter to test the resistance of each injector; it should be within specified range (usually around 12-16 ohms).
  3. If any injector is out of specification, replace it.
  4. Reconnect all components after testing.

6. Check Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Inspect the wiring and connectors for any signs of damage.
  3. Use a multimeter to test voltage output (should fluctuate between 0.1 to 0.9 volts).
  4. Replace any faulty oxygen sensors.

Tools Required:

• OBD-II scanner
• Fuel pressure gauge
• Multimeter
• Socket set
• MAF cleaner spray
• Smoke machine (optional)

Parts Required:

• Vacuum hoses (if damaged)
• MAF sensor (if faulty)
• Fuel filter (if clogged)
• Fuel pump (if malfunctioning)
• Fuel injectors (if defective)
• Oxygen sensors (if faulty)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow the engine to cool down before inspecting the intake system.