Fuel Tank Leak Detection Control Module -J909 - / Fuel Tank Pressure Sensor -G400-, Checking: Notes
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2017 Audi S5, 2016 Audi S5, 2016 Audi S4, 2015 Audi S5, and 2015 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.
- Models: all others test procedure A. Refer to TEST PROCEDURE A (ALL OTHERS) .
- Models: A8 test procedure B. Refer to TEST PROCEDURE B (A8 ONLY) .
General Description
The system can test the evaporative system integrity by using natural vacuum after the engine is shut off. The Engine Control Module -J623- monitors the ability of the system to maintain vacuum through signals sent from the Fuel Tank Pressure Sensor -G400- and the Fuel Tank Leak Detection Control Module -J909-. If the vacuum remains for a specified period of time, then there are no evaporative leaks, and a PASS is reported by the Engine Control Module -J623-. If there is a leak, the system either will not achieve a vacuum, or a vacuum cannot be maintained. Usually a fault can only be detected after a cold start.
Special tools and workshop equipment required
- Multimeter.
- Wiring Diagram.
- Scan Tool.
- Hand Vacuum pump.
- Evap Smoke Tester.
Test requirements
- Fuses OK.
- Battery voltage OK.
- Switch OFF All electrical and electronic accessories.
- Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
- Vehicles with Manual Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
- Coolant Temperature: ≥ 80° C.
- Observe all safety precautions: SAFETY PRECAUTIONS .
- View clean working conditions: CLEAN WORKING CONDITIONS .
- For Hybrid vehicles refer to: HIGH VOLTAGE SYSTEM GENERAL WARNINGS .