how to fix the P0174 code in my Volkswagen Passat B8 (2015-2022)?

Solution

1. Preparation

• Gather all tools and parts needed.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum tester, hose clamps, screwdriver
• Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a vacuum tester to confirm if there are any leaks.
• Replace any damaged hoses and ensure all connections are secure.

3. Check and Clean Mass Air Flow (MAF) Sensor

• Tools Required: MAF sensor cleaner, screwdriver
• Locate the MAF sensor on the intake duct.
• Disconnect the electrical connector and remove the MAF sensor using a screwdriver.
• Spray MAF sensor cleaner onto the sensor and let it dry completely before reinstalling.
• Reattach the MAF sensor and connector securely.

4. Test Fuel Pressure

• Tools Required: Fuel pressure gauge
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge to the test port and turn the ignition to the "ON" position without starting the engine.
• Check the fuel pressure reading against the manufacturer's specifications. If it's low, inspect the fuel pump and fuel filter for issues.

5. Inspect Fuel Injectors

• Tools Required: Multimeter, injector cleaning kit
• Disconnect the fuel injector connectors and test each injector with a multimeter to ensure they are receiving the correct voltage.
• If injectors are clogged, use an injector cleaning kit to clean them or replace them if necessary.

6. Reassemble and Reconnect

• Recheck all connections made during the repair process.
• Reconnect the negative battery terminal.
• Clear the P0174 code using the OBD-II scanner.