April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel Pump Delivery Quantity, Checking

Special tools and workshop equipment required

Hand held remote control (jumper).
Multimeter.
Electrical connector test lead set.
Fuel pressure test set (high pressure).
Measuring container, fuel-resistant.

Test conditions

Battery voltage 12.5 V
Fuel filter OK
Fuel tank at least ¹ /₄ filled.
Fuel pressure regulator OK.
Ignition switched off.

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK

Start diagnosis

-- Remove the fuel filler cap from fuel filler tube.

-- Remove rear seat bench. Refer to Repair information.

-- Remove cover retainers -arrows- from the right sealing flange.

Fig 1: Identifying Cover From Fuel Delivery Unit

GWWA20-1206

Courtesy of AUDI OF AMERICA, LLC

-- Disconnect the electrical harness connector -arrow- from the fuel delivery unit.

Fig 2: Disconnecting Electrical Harness Connector From Fuel Delivery Unit

GWWA20-10130

Courtesy of AUDI OF AMERICA, LLC

-- Connect a Hand held remote control (jumper) to terminal -1- of the fuel delivery unit and to vehicle battery (+).

-- Connect a jumper cable from a Electrical connector test lead set to terminal -5- of the fuel delivery unit and to vehicle Ground (GND).

Fig 3: A Jumper Cable From A Electrical Connector Test Lead Set Connected To Terminal Of Fuel Delivery Unit And To Vehicle Ground

GWWA20-1120

Courtesy of AUDI OF AMERICA, LLC

WARNING:

Fuel system is under pressure! Before opening the system, place rags around the connection area. Then release the pressure by carefully loosening the connection.

-- Disconnect the fuel return line -arrow- by pressing release buttons.

Fig 4: Disconnecting Fuel Return Line By Pressing Release Buttons

GWWA20-1212

Courtesy of AUDI OF AMERICA, LLC

-- Connect a fuel line from the Fuel pressure test set (high pressure) to the disconnected fuel return line and hold it in the measuring container.

Fig 5: Adapter V.A.G 1318/17-1 Connected To Disconnected Fuel Return Line And Placed In Measuring Container

GWWA20-1096

Courtesy of AUDI OF AMERICA, LLC

-- Press the switch on the Hand held remote control (jumper) and operate the fuel pump for 15 seconds.

-- Compare quantity of fuel delivered with minimum delivery rate in the diagram (cm³ /15s).

Fig 6: Delivery Rate Diagram

GWWA20-0260

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Voltage at the fuel pump with engine stopped and fuel pump running is approx. 2 volts less than battery voltage.

If minimum delivery quantity is not obtained, the following malfunctions may be present:

Fuel lines pinched.
Fuel filter plugged.
Fuel pump faulty.

-- If necessary, repair any pinched or plugged lines.

-- Replace the fuel filter. Refer to Repair information.

-- Replace the fuel pump. Refer to Repair information.

Assembly is performed in reverse order of removal. Note the following:

-- Install the rear seat bench. Refer to Repair information.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .