Pressure Retention Test

WARNING: This page is about a different variant/trim than selected.

-- Set the valve -D- to "Test". Increase the present pressure to 10 in. H2O (25 mbar).

Fig 1: Identifying Evaporative Emission (EVAP) Canister Purge Regulator Components

Courtesy of VOLKSWAGEN UNITED STATES, INC.

-- Observe the pressure gauge -C- and flow meter -E-. The fuel system is filled if the flow quantity decreases and the pressure increases to 10 in. H2O (25 mbar).

NOTE:

Depending on the level in the fuel tank, this procedure may take up to 3 minutes.

-- After the pressure has stabilized, set the valve -D- to "Hold".

After 5 minutes the pressure must not drop below 8 in H2O (20 mbar).

If the pressure is not maintained for 5 minutes, the leak should be localized as follows:

-- First, check the EVAP canister purge regulator valve 1 for leaks. Clamp off the hose to the EVAP canister purge regulator valve 1 using hose clamps up to 25 mm dia. 3094 -arrow-.

Fig 2: Clamping Off Hose To EVAP Canister Purge Regulator Valve 1 -N80- Using Hose Clamps Up To 25 Mm Dia. 3094

Courtesy of VOLKSWAGEN UNITED STATES, INC.

-- Repeat the pressure test by setting the valve -D- to "Test".

Fig 3: Identifying Evaporative Emission (EVAP) Canister Purge Regulator Components

Courtesy of VOLKSWAGEN UNITED STATES, INC.

-- Observe the pressure gauge -C- and flow meter -E-. The fuel system is filled if the flow quantity decreases and the pressure increases to 10 in. H2O (25 mbar).

-- After the pressure has stabilized, set the valve -D- to "Hold".

-- If the pressure now no longer falls, replace the EVAP canister purge regulator valve 1.

If the pressure still decreases, perform the "fuel system leak test". Refer to FUEL SYSTEM LEAK TEST .

After completing the work, perform the "Check tank ventilation system for leaks" guided function using the vehicle diagnosis, testing and information system VAS 5051.