Leakage detection for tank venting system USA:
WARNING: This page is about a different car, the 2003 BMW Z8, 2002 BMW Z8, 2001 BMW Z8, and 2000 BMW Z8. However, it is still accessible from the selected car via links, so may be relevant.
The tank leakage diagnostic module (see Figure , view A) serves to detect leakages for the tank venting system within the on-board diagnosis laid down by legislation.
The tank venting system is pressurized and the pressure loss is detected in the event of a leak.
The tank leakage diagnostic module is activated by the engine control unit and detects the pressure loss by way of the power consumption of the integrated pump. The air required for this purpose is supplied via the dust filter.
The pressure test line establishes the connection between fuel tank and filler neck. This enables a leak to be detected in the filler pipe - tank cap area.