Fuel Tank Leak Detection Control Module - J909-, CHECKING: General Description

The system tests the evaporative system integrity by applying a vacuum signal using the Leak Detection Pump -V144-, which is part of the Fuel Tank Leak Detection Control Module -J909-, to the fuel tank in order to create a small vacuum. The Engine Control Module -J623- then monitors the ability of the system to maintain the vacuum through signals sent from the sensor in 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.