Specified Value

• Specified value: 3 to 4 bar (43 to 58 psi).

If the fuel pressure is OK, check the residual pressure. Refer to RESIDUAL PRESSURE, CHECKING .

If Specification Is Exceeded

-- Check the return line between the fuel filter and the fuel pump for kinks or blockages.

If No Faults Are Detected

-- Pressure relief valve in fuel filter malfunctioning, replace fuel filter. Refer to FUEL FILTER .

If the Specification Is Not Obtained

-- Check the fuel pressure in front of the fuel filter as follows:

Check the Fuel Pressure in Front of the Fuel Filter

Fig 1: Fuel Supply Line At Fuel Filter

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Disconnect the fuel supply line -arrow- from the fuel filter. Disconnect the connector couplings. Refer to CONNECTOR COUPLINGS, SEPARATING .

-- Connect the Pressure Tester Kit - Hose 2 VAS 6550/2 to the connection -A- on the Pressure Tester Kit VAS 6550.

-- Connect the Pressure Tester Kit - Hose 1 VAS 6550/1 to the connection -B- on the Pressure Tester Kit VAS 6550.

Fig 2: Connecting Pressure Tester VAS 6550 Between Fuel Filter And Fuel Supply Line Using Hoses VAS 6550/1 And VAS 6550/2

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect the Pressure Tester Kit VAS 6550 between the fuel filter and the fuel supply line using the Pressure Tester Kit - Hose 1 VAS 6550/1 and the Pressure Tester Kit - Hose 2 VAS 6550/2.

-- Pull on the connector couplings to make sure they are secure.

-- Make sure that the drain valve -C- on the Pressure Tester (Diesel) -1- is shut.

Fig 3: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- The shut-off valves -A and B- on the Pressure Tester Kit -1- are opened.

-- Activate the fuel pump with output diagnostic test mode to build fuel pressure.

-- Repeat fuel pump output diagnostic test mode to build the fuel pressure. See Activate the fuel pump with the output diagnostic test mode to build fuel pressure.  above.

If Specified Value Is Achieved

-- Check the fuel line between the fuel filter and the engine compartment for possible kinks or blockages.

-- Check the fuel line between the fuel filter and the engine compartment for leaks and damage.

If No Faults Can Be Found

-- The fuel filter is clogged. Replace the fuel filter FUEL FILTER .

-- Pressure relief valve in fuel filter malfunctioning, replace fuel filter. Refer to FUEL FILTER .

If the Specification Is Not Obtained

Proceed as follows to check the fuel pressure at the fuel delivery unit:

Check the Fuel Pressure on the Fuel Delivery Unit

-- Remove the bench seat. Refer to Rear Seat Backrest Overview .

-- If equipped, remove the Fuel Pump Control Module -J538- -2- from the cover -1-.

Fig 4: Identifying Cover With Fuel Pump Control Module J538

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Unclip the right cover -1- at the tabs -arrows- using the Trim Removal Wedge 3409.

Fig 5: Identifying Right Cover

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Remove the fuel lines -1- from the flange. Disconnect the connector couplings. Refer to CONNECTOR COUPLINGS, SEPARATING .

Fig 6: Fuel Lines At Flange

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-- Connect the Pressure Tester Kit VAS 6550 -1- between the fuel line and the fuel delivery unit using the Pressure Tester Kit - Hose 1 VAS 6550/1 and Pressure Tester Kit - Hose 2 VAS 6550/2.

Fig 7: Identifying Fuel Line And Fuel Delivery Unit

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

• Pressure Tester Kit - Hose 1 VAS 6550/1 -2- between the fuel line -5- and shut-off valve -B-
• Pressure Tester Kit - Hose 2 VAS 6550/2 -1- between the fuel delivery unit -4- and shut-off valve -A-

-- Pull on the connector couplings to make sure they are secure.

-- Make sure that the drain valve -C- on the Pressure Tester (Diesel) -1- is shut.

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

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- The shut-off valves -A and B- on the Pressure Tester Kit -1- are opened.

-- Activate the fuel pump with the output diagnostic test mode to build fuel pressure. See Activate the fuel pump with the output diagnostic test mode to build fuel pressure.  above.

If Specified Value Is Achieved

-- Check the fuel lines for possible restrictions (kinks) or blockages.

-- Check the fuel line for leaks and damage.

If Specification Is Not Obtained

-- Remove the fuel delivery unit. Refer to FUEL DELIVERY UNIT  and inspect it for debris.

-- Make sure all hoses -arrows- are connected.

Fig 9: Identifying Delivery Unit Fuel Hoses

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Check the fuel lines for possible restrictions (kinks) or blockages.

-- Check the fuel lines for leaks and damage.

If No Malfunction Can Be Found

-- If the fuel pump is faulty, replace the fuel delivery unit. Refer to FUEL DELIVERY UNIT .