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Fuel Tank Leak Detection Control Module, Checking: Notes

Observe all safety precautions: SAFETY PRECAUTIONS .

View clean working conditions: CLEAN WORKING CONDITIONS .

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals:

For wiring diagrams, component locations, and connector views, Refer to the appropriate System Wiring Diagram.

The following procedure is used to diagnose the Fuel Tank Lead Detection Control Module -J909- which is controlled by Engine Control Module -J623-.

Special tools and workshop equipment required 

Test requirements 

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis 

-- Remove the left rear underbody protective cover.

-- Using a Multimeter, Check the Fuel Tank Lead Detection Control Module -J909- electrical harness connector terminals 1 to 3 for voltage.

Fig 1: Disconnecting Fuel Tank Lead Detection Control Module
GWWA20-10967Courtesy of AUDI OF AMERICA, LLC

-- Switch the ignition ON.

Specified value: Battery voltage.

-- Switch the ignition OFF.

-- Continue test according to the following table:

Value Cause Test
If the specified value was not obtained: Open or shorted circuit FUEL TANK LEAK DETECTION CONTROL MODULE, CHECKING => Checking wiring 
If the specified value was obtained: Check reference signal circuit FUEL TANK LEAK DETECTION CONTROL MODULE, CHECKING => Checking wiring