3.0L TDI vehicles

Courtesy of AUDI OF AMERICA, LLC

-- Disassemble the Diesel Pressure Tester Kit - Pressure Regulator Valve:VAS 6551/6  and remove it with the measuring container.

• Fuel delivery rate and pressure test in the fuel supply is OK.
• Diesel Pressure Tester Kit - Hose Adapter:VAS 6551/7-2  is connected to the fuel supply hose and to the Diesel Pressure Tester Kit:VAS 6551  .
• Vehicle Diagnostic Tester is connected.

-- Connect the Diesel Pressure Tester Kit - Hose Adapter:VAS 6551/7-1  to the fuel supply hose for the high pressure pump and to the Diesel Pressure Tester Kit:VAS 6551  .

Courtesy of AUDI OF AMERICA, LLC

Continuation for All Vehicles:

Fig 1: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

-- Switch on the Diesel Pressure Tester Kit:VAS 6551  -item 1- by pressing the On/Off  button.

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

• The levers point in the flow direction.

-- Connect the Vehicle Diagnostic Tester.

-- Switch the ignition on.

-- Select Diagnostic  and start.

-- Select the Select individual test  button and select the following tree structure consecutively:

• Drivetrain 
• Select the engine code and engine 
• 0001 - OBD-capable systems 
• 0001 - Engine Electronics 
• 0001 - Engine electronics, functions 
• 0001 - Fuel pump activation 
• Perform the test 

-- Start the fuel pump and let it run for 15 seconds.

-- Read the fuel pressure on the Diesel Pressure Tester Kit:VAS 6551  .

• Specified value: 3.8 to 5.8 bar (55.11 to 84.12 psi).

If the specified value is not reached, although the fuel delivery rate was OK:

• The high pressure pump overflow valve is not OK

If specified value is not reached:

• The fuel return line is blocked or kinked.

Assembling

Assemble in the reverse order of removal. Note the following:

• The ignition must be off.

NOTE:

Decrease the fuel pressure by opening the shut-off valves -B and C- and allowing the fuel drain into the measuring container before removing the pressure tester -1-.

Fig 2: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

-- Remove the Diesel Pressure Tester Kit:VAS 6551  with the connecting lines.

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

-- Install the engine cover. Refer to ENGINE COVER, REMOVING AND INSTALLING .