Fuel pump failure Q5 FY

Tools Required

• OBD-II Scanner
• Fuel pressure gauge
• Multimeter
• Basic hand tools (screwdrivers, wrenches)
• Safety equipment (gloves, safety glasses)

Step-by-Step Diagnosis

1. Check for Diagnostic Trouble Codes (DTCs):

   • Connect the OBD-II scanner to the diagnostic port.
   • Read any stored codes that may indicate fuel system issues, such as P0087 (Fuel Rail/System Pressure - Too Low).

2. Listen for Fuel Pump Operation:

   • Turn the ignition key to the "ON" position (do not start the engine).
   • Listen for a humming noise from the fuel tank which indicates the pump is running.
   • Absence of sound may indicate a failed pump.

3. Check Fuel Pressure:

   • Connect a fuel pressure gauge to the Schrader valve on the fuel rail.
   • Turn the ignition to the "ON" position without starting the engine.
   • Verify that fuel pressure meets the specifications (consult service manual for specific pressure values, typically around 50-60 psi).
   • If pressure is low or drops rapidly, it indicates a failing pump or clogged filter.

4. Inspect Fuel Pump Electrical Connections:

   • Disconnect the fuel pump electrical connector.
   • Use a multimeter to check for power (12V) and ground at the connector when the ignition is "ON."
   • Corroded or loose connections can impede pump operation.

Repair Instructions

Tools Required

• Replacement fuel pump module
• Fuel line disconnect tools
• Torque wrench
• Jack and jack stands

Step-by-Step Replacement

1. Relieve Fuel System Pressure:

   • Locate the fuel pump relay or fuse and remove it.
   • Start the engine and let it run until it stalls to relieve pressure.
   • Disconnect the battery to prevent accidental starts.

2. Access the Fuel Pump:

   • Raise the vehicle using a jack and secure with jack stands.
   • Remove the rear seat cushion to access the fuel pump cover.
   • Remove the fuel pump access cover using a screwdriver.

3. Remove the Fuel Pump:

   • Disconnect the electrical connector and fuel lines from the pump module.
   • Use the appropriate tool to remove the retaining ring securing the pump.
   • Carefully lift the fuel pump module out of the tank.

4. Install the New Fuel Pump:

   • Transfer any necessary components (like the fuel level sensor) from the old pump to the new one.
   • Insert the new fuel pump module into the tank.
   • Secure it with the retaining ring, ensuring a proper seal to prevent leaks.

5. Reconnect Fuel Lines and Electrical Connector:

   • Ensure all connections are secure and free of leaks.
   • Reinstall the fuel pump access cover and rear seat cushion.

6. Reinstall Fuel Pump Relay/Fuse and Battery:

   • Reconnect the battery.
   • Reinstall the previously removed relay or fuse.

7. Test the System:

   • Turn the ignition to "ON" and listen for the fuel pump operation.
   • Start the engine and check for proper operation and absence of leaks.

8. Final Check:

   • Use the OBD-II scanner to clear any stored codes.
   • Verify that the check engine light remains off and that the vehicle runs smoothly.

By following these steps, you should be able to diagnose and replace a faulty fuel pump in an Audi Q5 FY effectively. Always refer to the specific vehicle service manual for detailed specifications and safety precautions.