Fuel Pump, Checking Fuel Pressure

WARNING: This page is about a different car, the 2016 Audi Q5, 2015 Audi Q5, and 2014 Audi Q5. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

For 4-cylinder and 6-cylinder generation I engines (refer to DETERMINING ENGINE GENERATION ), the Transfer Fuel Pump -G6- is checked under the underbody in the fuel tank together with the Auxiliary Fuel Pump -V393-.

For 4-cylinder and 6-cylinder generation II engines (refer to DETERMINING ENGINE GENERATION ) the Auxiliary Fuel Pump -V393- is no longer installed, so only the Transfer Fuel Pump -G6- is checked.

Special tools and workshop equipment required

Diesel Pressure Tester Kit VAS6551
Diesel Pressure Tester Kit - Adapter Set VAS6551/5

Procedure

Follow all test requirements, refer to TEST CONDITIONS .

WARNING:

Very hot fuel can burn your skin.

In extreme cases the temperature of the fuel lines and/or the fuel can go up to 100 °C (212 °F). 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.

CAUTION:

Always observe the rules for cleanliness when working on the injection system, refer to CLEAN WORKING CONDITIONS .

Version 1:

NOTE:

Ignore item -2-.

-- Disconnect the fuel line -1-.

Fig 1: Identifying Fuel lines -1- & -2-

Courtesy of AUDI OF AMERICA, LLC

Version 2:

Fig 2: Identifying Fuel Hoses

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Ignore items -1 and 3-.

-- Disconnect the fuel supply hose -2-.

Continuation for All Vehicles:

Fig 3: Connecting Diesel Pressure Tester Kit - Adapter Set - Connection Hose 2 VAS6551/5-2 On The Fuel Supply Line -1-

Courtesy of AUDI OF AMERICA, LLC

-- Connect the Diesel Pressure Tester Kit - Adapter Set - Connection Hose 2 VAS6551/5-2 on the fuel supply line -1- and secure with hose clamp.

-- Connect the Diesel Pressure Tester Kit - Adapter Set - Adapter 1 VAS6551/5-1 to the fuel supply hose -2- secure it with a hose clamp and install the Diesel Pressure Tester Kit - Adapter Set - Connection Hose 4 VAS6551/5-4.

NOTE:

The Diesel Pressure Tester Kit VAS6551 is switched in the fuel supply line.

-- Connect the Diesel Pressure Tester Kit VAS6551 with the Diesel Pressure Tester Kit - Adapter Set - Connection Hose 2 VAS6551/5-2, Diesel Pressure Tester Kit - Adapter Set - Connection Hose 3 VAS6551/5-3 and Diesel Pressure Tester Kit - Adapter Set - Connection Hose 4 VAS6551/5-4 on the fuel supply hose.

Fig 4: Connecting Diesel Pressure Tester Kit VAS6551

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

Risk of fuel leak.

Make sure that the drain -C- is closed.
The lever is perpendicular to the direction of flow.

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

The levers point in the direction of flow.

Fig 5: Connecting Diesel Pressure Tester Kit VAS6551

Courtesy of AUDI OF AMERICA, LLC

-- 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

-- Push Start : the fuel pump starts.

-- Let the fuel pump run until the highest fuel pressure is reached.

Specified values:

4-cylinder and 6-cylinder generation II engines: at least 3.5 bar (50.76 psi)

If the specification is not obtained:

Check the connection between the Diesel Pressure Tester Kit VAS6551 and the fuel supply line for leaks.
Checking the Diesel Pressure Tester Kit VAS6551 for leaks.
Check fuel lines and their connections for leaks.
The fuel filter is clogged.

-- Check the Transfer Fuel Pump -G6- fuel delivery rate, refer to Transfer Fuel Pump -G6-, CHECKING, 4- AND 6-CYLINDER GENERATION II ENGINE .

NOTE:

Check fuel system for leaks.