what causes the fuel gauge to be inaccurate in my Volkswagen Passat B8 (2015-2022)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical shorts.
• Allow the vehicle to cool down before working on the fuel system.

2. Access Fuel Sending Unit

• Tools Required: Socket set, screwdrivers, safety glasses, gloves.
• Remove the rear seat or access panel to reach the fuel tank access point.
• Disconnect any electrical connectors and fuel lines carefully.
• Remove the retaining ring or screws securing the fuel pump assembly.

3. Inspect and Test Fuel Sending Unit

• Remove the fuel sending unit from the tank.
• Check the float arm for free movement; make sure it is not stuck or damaged.
• Test the resistance of the sending unit using a multimeter. It should show a range of values as the float moves from empty to full.
• If defective, replace the fuel sending unit.

4. Reassemble Components

• Reinstall the sending unit carefully back into the tank, ensuring proper sealing.
• Reconnect all electrical connections and fuel lines securely.
• Reinstall the access cover or rear seat.

5. Final Checks

• Reconnect the battery.
• Turn on the ignition without starting the engine to check if the fuel gauge registers correctly.
• If the gauge is still inaccurate, consider replacing the gauge cluster or further diagnosing the wiring harness.