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Fuel Pump Delivery Quantity, Checking

Special Tools And Workshop Equipment Required

Switched remote control (jumper).
multimeter.
Electrical connector test lead set.
Fuel pressure test set.
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 appropriate service information.

-- Remove the floor sealing cover -1-.

Fig 1: Fuel Pump Control Module, Retaining Clips & Floor Sealing Cover

GWWM20-0321

Courtesy of AUDI OF AMERICA, LLC

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

Fig 2: Identifying Fuel Delivery Unit Connector

GWWA20-1067

Courtesy of AUDI OF AMERICA, LLC

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

-- Connect a jumper wire from terminal -5- of the fuel delivery unit 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 to the disconnected fuel return line and hold it in the measuring container.

Fig 5: Adapter VAG 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 remote control (jumper) and operate the fuel pump for 15 seconds.

-- Compare quantity of fuel delivered with minimum delivery rate in the diagram (cm³ /30 sec.).

Fig 6: Fuel Quantity Graph

GWWN20-10138

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.

If the filter is restricted;

-- Replace the fuel filter. Refer to appropriate service information.

If the fuel pump is faulty;

-- Replace the fuel pump. Refer to appropriate service information.

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

-- Install the rear seat bench. Refer to appropriate service 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 .