Fuel Tank Leak Detection Control Module -J909 - / Fuel Tank Pressure Sensor -G400-, Checking: Notes

• 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 .