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Home >> Audi >> 2017 >> S6 Premium Plus >> Repair and Diagnosis (Single Page) >> Engine Mechanical >> Fuel System >> Fuel System (EVAP Leak Tester - General Information) >> 20 Fuel Supply >> Fuel System EVAP Leak Test >> EVAP System Leak Test, Vehicles With Fuel Tank Leak Detection Control Module (NVLD) >> Fuel Tank Leak Detection Control Module, Testing For Internal Leaks
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Fuel Tank Leak Detection Control Module, Testing For Internal Leaks

CAUTION:

Clamp Only Soft Rubber Lines When Isolating A Leak. To Avoid Risk Of Damage, Never Clamp Hard Plastic Lines!

-- Clamp off fuel tank leak detection control module outlet (filter side) using Hose Clamps Up to 25 mm Dia.:VAS3094  or equivalent by removing the filter connection and plugging the port on the fuel tank leak detection control module tightly with a soft rubber plug.

NOTE:

Vehicles Equipped With The Fuel Tank Leak Detection Control Module May Require One Of Two Different Test Adapters That May Vary Depending On The Model.

-- Attach Evaporative Emissions Tester - Adapter 57:KLI9210/57  or T adapter between the EVAP system and the EVAP Canister Purge Regulator Valve 1 -N80-.

NOTE:

No Special Tool T Adapter Is Available At This Time. The T Adapter May Have To Be Fabricated If It Is Required For Testing.

-- Attach the test hose from the Evaporative Emissions Tester:KLI9210  to the adapter.

NOTE:

Make Sure Tester Is Calibrated To 10 Inches Of Water. Refer to EVAP SYSTEM, TESTING .

-- Set control valve -2- from "Hold" to "Test".

GWWUS20-A160Courtesy of AUDI OF AMERICA, LLC
NOTE:

Calibrate Evaporative Emissions Tester:KLI9210  To 10 in. Of Water Prior To Connecting The To The Vehicle.

-- Increase the current pressure until it reaches 10 in. H2O (25 mbar).

-- Monitor the pressure gauge -3- and the flow meter -4-. Allow the flow rate to decrease. If pressure builds to 10 in. H2O (25 mbar), the fuel system is full.

NOTE:

Depending On The Level Of Fuel In The Tank, It May Take Up To Three Minutes To Notice A Visible Decrease In Flow Rate.

-- After the pressure has stabilized, set control valve -2- to "Hold".

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

If pressure drops below 8 in. of water in five minutes then find leak with the smoke tester, soapy water and/or isolating components by clamping them off individually.

If Fuel System Pressurization Does Not Stabilize: 

-- Verify all fuel system outlets have been sealed before continuing.

NOTE:

Any Flow Shown On Flow Meter Indicates A Leak.

If Flow Meter On Tester Registers Flow Near Or Above Preset Pressure: 

CAUTION:

Clamp Only Soft Rubber Lines When Isolating A Leak. To Avoid Risk Of Damage, Never Clamp Hard Plastic Lines!

-- Clamp off hose -arrow- leading from EVAP Canister Purge Regulator Valve 1 -N80- to intake manifold.

If No Flow Is Present And The Pressure Drop Is Above 8 In. Of Water After Five Minutes: 

-- Replace fuel tank leak detection control module and repeat test.

If Meter Indicates No Flow After Test: 

-- Perform quality check and return vehicle to customer.