Test Sequence:

WARNING: This page is about a different car, the 2023 Volkswagen Atlas. However, it is still accessible from the selected car via links, so may be relevant.

-- Connect the Vehicle Diagnostic Tester.

-- Select the fuel pump output diagnostic test mode in OBD.

NOTE:

The fuel pump is now activated to build up the fuel pressure.

If the output diagnostic test mode was performed several times in succession, the engine may need to be started briefly before repeating the output diagnostic test mode.

-- Read the fuel pressure on the pressure gauge.

Specified value: greater than or equal to 4 bar (58.01 psi).

-- End the OBD and turn off the ignition.

-- Observe the decrease in pressure on the pressure gauge. The pressure must not drop below 3.0 bar (43.5 psi) after 10 minutes.

If the Pressure Drops:

-- Check all of the fuel lines for leaks and damage.

If No Faults Can Be Found:

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

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Make sure that the drain valve -C- on the :VAS6550 -1- is closed.

-- The shut-off valves -A and B- on the :VAS6550 -1- are opened.

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

-- Close the shut-off valve -A- on the pressure gauge immediately after the pressure has been reached. The lever is perpendicular to the flow direction.

If the Pressure Drops Again (Leak on Fuel Tank Side):

Proceed as follows to check residual pressure on the fuel delivery unit. Refer to Residual Pressure in Fuel Delivery Unit, Checking: .