FUEL TANK - LEAK DETECTION, VEHICLES WITH Fuel Tank Pressure Sensor -G400-
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Audi SQ5, 2024 Audi Q5 e, 2024 Audi Q5, 2023 Audi SQ5, and 2023 Audi Q5 e. However, it is still accessible from the selected car via links, so may be relevant.
- The function of the leak detection system is based on the premise that the fuel system creates a natural vacuum when the fuel in the fuel tank -4- becomes colder.
- The Fuel Tank Pressure Sensor -G400- -item 3- senses the vacuum in the vent line -2- for the EVAP canister -1-. The Fuel Tank Leak Detection Control Module -J909- -item 5- is attached directly to the wall of the fuel tank and monitors the temperature inside the fuel tank. The system is considered to be sealed if the measured vacuum is 2.5 mbar (0.04 psi). If there is no vacuum, then there is a leak in the fuel system, which will result in an entry in the engine control module DTC memory.
6 - Bleeder Line to Engine