Transfer Fuel Pump - G6-, VEHICLES WITH 3.0L (V6)/4.2L (V8) ENGINES FROM 06/2010

WARNING: This page is about a different variant/trim than selected.

Special tools and workshop equipment required

Diesel Pressure Tester KitVAS6551
Diesel Pressure Tester Kit - Adapter Set VAS6551/5
Pressure Regulator ValveVAS6551/6
Vehicle Diagnostic Tester
Measuring container, fuel-resistant

A - Check Fuel Delivery Rate

Fig 1: Identifying Fuel Filler Cap (Fuel Cap)

Courtesy of AUDI OF AMERICA, LLC

-- Follow all test requirements, refer to TEST CONDITIONS .

-- Follow the guidelines for clean working conditions, refer to CLEAN WORKING CONDITIONS .

-- Open the fuel filler door.

-- Remove the fuel filler cap -arrow-.

Fig 2: Fuel Filler Cap Location

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WARNING:

There is a risk of burns due to hot fuel.

The temperature of the fuel lines or fuel may reach 100 °C (212 °F) after stopping the engine. Let the fuel cool down before opening any line connections otherwise there is a danger of scalding.
Wear safety gloves
Wear protective eyewear.

There is a risk of injury because the fuel is under high pressure.

To reduce pressure in fuel system, lay a clean cloth around the connector and carefully loosen connector.

-- Open the clamp and disconnect the fuel hose -arrow-.

-- Connect the Diesel Pressure Tester KitVAS6551 to the fuel supply line using the Diesel Pressure Tester Kit - Adapter Set - Connection Hose 2VAS6551/5-2 and secure with a hose clamp.

Fig 3: VAS6551/6

Courtesy of AUDI OF AMERICA, LLC

-- Attach the Pressure Regulator ValveVAS6551/6 and hold the hose in a fuel-resistant measuring container.

-- Switch on the Diesel Pressure Tester KitVAS6551 -1- by pressing the On/Off button.

Fig 4: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

NOTE:

To measure the fuel delivery rate, there must be an initial pressure inside the fuel supply line against which the fuel pump must work during the measuring. This initial pressure is adjusted using the Pressure Regulator ValveVAS6551/6 as follows:

-- Open the shut-off valves -A and B-.

The levers point in the direction of flow.

CAUTION:

Risk of fuel leak.

The shut-off valve -C- must be closed.
The lever is perpendicular to the direction of flow.

-- Connect the Vehicle Diagnostic Tester.

-- Turn on the ignition and select the following menu items on the Vehicle Diagnostic Tester:

OBD
Engine Electronics
Basic Setting
Transfer Fuel Pump Test

-- Press Start : The fuel pump starts.

-- Turn the adjusting screw -1- on the Pressure Regulator ValveVAS6551/6 to create an initial pressure in the fuel system until the correct initial pressure value is reached.

Fig 5: Identifying Pressure Regulator Valve Adjusting Screw

Courtesy of AUDI OF AMERICA, LLC

Specified value: 4 bar (58 psi) pressure:

-- Do not turn the adjusting screw -1- any more.

-- Press the Stop button.

-- Empty measuring container.

-- To measure, press the Start button again and let the fuel pump run for 15 seconds.

-- After 15 seconds, press the Stop button.

-- Check the amount of fuel in the measuring container.

Specified value: Minimum delivery rate: 750 cm³ /15 s.

If the Minimum Delivery Rate Is Attained

Fuel supply and fuel pump are OK
However, there may be a malfunction in the fuel return. For Fault Finding, perform an "Entire system pressure test", refer to Transfer Fuel Pump - G6-, VEHICLES WITH 3.0L (V6)/4.2L (V8) ENGINES FROM 06/2010 .

If Minimum Delivery Quantity Is Not Obtained, the Following Malfunctions May Be Present:

The fuel pump or fuel pressure regulator in the fuel tank is faulty.
Fuel supply line is pinched.

NOTE:

To locate the fault in more detail, perform the "pressure test in the fuel supply line", described as follows.

B - Pressure Test in the Fuel Supply Line

Fig 6: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

Connect the measuring setup as if measuring the delivery quantity.
Vehicle Diagnostic Tester still connected.

-- Switch on the Diesel Pressure Tester KitVAS6551 -1- by pressing the On/Off button.

-- Open the shut-off valve -A-.

The lever points in the direction of flow.

CAUTION:

Risk of fuel leak.

The shut-off valves -B and C- must be closed.
The levers face perpendicular to the flow direction.

-- Press Start on the display of the Vehicle Diagnostic Tester: The fuel pump starts.

-- After 15 seconds, press the Stop button.

-- Read the fuel pressure in the Diesel Pressure Tester KitVAS6551.

Specified value: minimum 6 bar (87 psi).

If Specified Value Is Obtained, Although the Fuel Delivery Unit Is Not OK.

Fuel supply line is pinched.

If the Specification Is Not Attained:

The fuel pump or fuel pressure regulator in the fuel tank is faulty.

NOTE:

To also locate malfunctions in the fuel return line, at the fuel filter or at the high pressure pump overflow valve, the "Entire system pressure test" must be performed as described in the following.

Before replacing the measuring system, reduce the fuel pressure by opening the shut-off valves -B and C- and allowing the fuel to drain into the measuring container.

Fig 7: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

-- Disassemble the Pressure Regulator ValveVAS6551/6 and remove it with the measuring container.

Fig 8: VAS6551/6

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C - Entire System Pressure Test. Refer to Transfer Fuel Pump - G6-, VEHICLES WITH 3.0L (V6)/4.2L (V8) ENGINES FROM 06/2010 .

Fig 9: VAS6551

Courtesy of AUDI OF AMERICA, LLC

Fuel delivery rate and pressure test in the fuel supply is OK.
The Diesel Pressure Tester Kit - Adapter Set - Connection Hose 2 VAS6551/5-2 must be connected to the fuel supply line and the Diesel Pressure Tester Kit VAS6551.
Vehicle Diagnostic Tester is connected.

-- Connect the Diesel Pressure Tester Kit - Adapter Set - Adapter 1 VAS6551/5-1 to the fuel supply hose -1- to the fuel filter and secure it with a hose clamp.

-- Connect the Diesel Pressure Tester Kit - Hose 2 VAS6551/2.

-- Connect the Diesel Pressure Tester Kit - Hose 2 VAS6551/2 to the Diesel Pressure Tester Kit VAS6551.

NOTE:

The Diesel Pressure Tester KitVAS6551 is inserted in the fuel supply line.

-- Switch on the Diesel Pressure Tester KitVAS6551 -1- by pressing the On/Off button.

Fig 10: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

-- Open the shut-off valves -A and B-.

The levers point in the direction of flow.

CAUTION:

Risk of fuel leak.

The shut-off valve -C- must be closed.
The lever is perpendicular to the direction of flow.

-- Turn on the ignition and select the following menu items on the Vehicle Diagnostic Tester:

OBD
Engine Electronics
Basic Setting
Transfer Fuel Pump Test

-- Press Start : The fuel pump starts.

-- Read the fuel pressure in the Diesel Pressure Tester KitVAS6551.

Specified value: 3.8 to 5 bar (55 to 72.5 psi).

If Specified Value Is Not Reached, Although the Fuel Delivery Rate Was OK:

The high pressure pump overflow valve is not OK

If the Specified Value Is Exceeded By More Than 6 bar (87 psi)

The fuel filter is clogged or the fuel return line is kinked

Assembling

Assembly is performed in the reverse order of disassembly, noting the following:

The ignition must be off.

NOTE:

Decrease the fuel pressure by opening the drains -B and C- and letting the fuel run into the measuring container before removing the pressure gauge -1-.

Fig 11: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

-- Remove the Diesel Pressure Tester KitVAS6551 with the connecting cables.

-- Secure the fuel supply line with a hose clamp and then pull on it to make sure the fuel supply line is secure.