How to fix fuel pump failure Audi A6

Fuel Pump Failure in Audi A6 C7 (2011-2018)

Symptoms of Fuel Pump Failure:

1. Engine Stalling: The engine may start but then stall shortly after.
2. Difficulty Starting: Extended cranking time or failure to start.
3. Loss of Power: Noticeable power loss while driving, especially under load.
4. No Sound from Fuel Pump: Normally, you should hear the fuel pump priming when the ignition is switched on.
5. Check Engine Light: May illuminate with a relevant diagnostic trouble code (DTC).

Tools Required:

• Jack and Jack Stands
• Socket Set and Ratchet
• Fuel Pressure Gauge
• Multimeter
• Screwdrivers (Flathead and Phillips)
• OBD-II Scanner
• Safety Glasses and Gloves

Repair Instructions:

Step 1: Safety Precautions

• Disconnect the Battery:
  • Remove the negative terminal to prevent electrical shorts.
• Relieve Fuel System Pressure:
  • Locate the fuel pump relay and remove it. Start the engine and let it run until it stalls. This relieves pressure in the fuel lines.

Step 2: Access the Fuel Pump

• Remove Rear Seat:
  • Lift and remove the rear seat cushion to access the fuel pump cover.
• Remove Fuel Pump Cover:
  • Use a screwdriver to remove screws securing the cover over the fuel pump.

Step 3: Remove the Fuel Pump

• Disconnect Electrical Connectors:
  • Carefully disconnect all electrical connectors to the fuel pump.
• Disconnect Fuel Lines:
  • Use a line disconnect tool to safely detach the fuel lines. Be prepared for residual fuel spillage.
• Remove Fuel Pump Retaining Ring:
  • Use a special fuel pump removal tool or a suitable wrench to unscrew the retaining ring.
• Remove the Fuel Pump:
  • Gently lift the fuel pump assembly out of the tank. Note the orientation for reinstallation.

Step 4: Install the New Fuel Pump

• Transfer Components:
  • If necessary, transfer any components (such as the fuel level sensor) from the old pump to the new one.
• Install the New Pump:
  • Carefully lower the new pump into the tank, ensuring it is correctly seated.
• Secure with Retaining Ring:
  • Tighten the retaining ring to secure the pump.

Step 5: Reassembly

• Reconnect Fuel Lines and Electrical Connectors:
  • Ensure all connections are secure and properly seated.
• Replace Fuel Pump Cover and Rear Seat:
  • Secure the cover and reattach the rear seat cushion.

Step 6: Test the System

• Reconnect Battery:
  • Reattach the battery terminal.
• Prime the Fuel System:
  • Turn the ignition on for a few seconds before starting to allow the pump to prime.
• Start the Engine:
  • Start the engine and check for leaks around the fuel pump area.
• Check for DTCs:
  • Use the OBD-II scanner to clear any stored codes and verify no new codes appear.

Following these steps should resolve the fuel pump failure in your Audi A6 C7. Always ensure to follow safety precautions when working with fuel systems.