Transfer Fuel Pump -G6-, CHECKING (A5 FROM MY 2012, A4/S4 FROM MY 2013 WITH 4-CYLINDER AND 6-CYLINDER ENGINES, RS5 FROM MY 2012, RS4)

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2016 Audi S4, 2016 Audi A4 Quattro, 2016 Audi A4, 2015 Audi S4, and 2015 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Pressure Tester Kit VAS6550 with Pressure Tester Kit - Hose 2 VAS6550/2
Pressure Regulator Valve VAS6550/4
Vehicle Diagnostic Tester
Measuring container, fuel-resistant

A - Check Fuel Delivery Rate

Fig 1: Identifying Cap -2-

Courtesy of AUDI OF AMERICA, LLC

-- Follow all test requirements. Refer to TEST CONDITIONS .

-- Release and open the fuel filler door.

-- Remove the cap -2- for the fuel filler -1-.

NOTE:

Ignore item -3-.

WARNING:

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.

Vehicles with 4-Cylinder and 6-Cylinder Engines

Fig 2: Identifying Fuel Line

Courtesy of AUDI OF AMERICA, LLC

-- Disconnect the fuel line -2-. Disconnect the connector couplings. Refer to CONNECTOR COUPLINGS, SEPARATING .

RS4, RS5

Fig 3: Pushing Hose Coupling -2- Downward -Arrow A-, Then Press Release Buttons -Arrow B-

Courtesy of AUDI OF AMERICA, LLC

-- Fold the boot -1- downward and disconnect the hose coupling -2-. Refer to CONNECTOR COUPLINGS, SEPARATING .

Continuation for All Vehicles

Fig 4: Identifying Diesel Pressure Tester Kit VAS 6550 With Diesel Pressure Tester Kit - Hose 2 VAS 6550/2

Courtesy of AUDI OF AMERICA, LLC

-- Connect the Diesel Pressure Tester Kit VAS6550 with the Diesel Pressure Tester Kit - Hose 2 VAS6550/2 to the fuel supply line.

-- Connect the Pressure Regulator Valve VAS6550/4 and hold the hose in a fuel-resistant measuring container.

NOTE:

The illustration shows the measuring setup for a 4-cylinder engine.

-- Turn the Pressure Tester Kit VAS6550 -1- on by pressing the On/Off button.

Fig 5: 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.

NOTE:

In order to measure the fuel delivery rate, there must be an initial pressure inside the fuel line against which the fuel pump must work during the measuring. Adjust the initial pressure using the Pressure Regulator Valve VAS6550/4 as follows:

-- 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
Empty Fuel Tank

-- Push Start : the fuel pump starts.

-- Turn the adjusting screw -1- on the Pressure Regulator Valve VAS6550/4 to create an initial pressure in the fuel system until the correct initial pressure value is reached.

Fig 6: Identifying Pressure Regulator Valve Adjusting Screw

Courtesy of AUDI OF AMERICA, LLC

Specified value: 4.3 bar (62.3 psi) pressure

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

-- 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 800 cm³ /15 s.

If the Minimum Delivery Rate Is Attained

The fuel delivery unit with the fuel filter, fuel pressure regulator and fuel supply line is OK.

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

Fuel delivery unit faulty.
Fuel filter is blocked or the fuel pressure regulator is faulty (bother are in the locking flange).
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 7: 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.

-- Turn the Pressure Tester Kit VAS6550 -1- on by pressing the On/Off button.

-- 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.

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

-- If the fuel flows without bubbles, close the drain -B-, so that the fuel pressure increases.

The lever is perpendicular to the direction of flow.

-- Read the fuel pressure in the Pressure Tester Kit VAS6550:

Specified value: 5.0 to 8.0 bar (72.51 to 116.03 psi)

-- Press the Stop button.

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

Fuel filter in the locking flange is blocked or the fuel supply line is crushed.

If the Specification Is Not Attained

Fuel delivery unit or fuel pressure regulator (in the locking flange) is faulty.

C - Checking Residual Pressure

-- Watch the pressure fall on the Pressure Tester Kit VAS6550 while checking the holding pressure and checking for leaks:

After 10 minutes there must be a residual pressure of at least 3 bar (43 psi).

If the Residual Pressure Drops Below 3 bar (43 psi)

Check fuel lines and their connections for leaks.
The fuel pump check valve in the fuel pump leaks: replace the fuel delivery unit. Refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR, REMOVING AND INSTALLING .

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

Courtesy of AUDI OF AMERICA, LLC

-- Remove the Pressure Tester Kit VAS6550 with the connecting lines.

-- Attach the fuel supply line so that it clicks into place.

-- Press the fuel supply line on again and pull to make sure the connector coupling is engaged correctly.