LDP EVAP System

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.

The LDP is integrated into the EVAP system and can have two functions. The LDP can:

Pressurize the EVAP system and detect a drop in pressure that would indicate a leak
Function as the EVAP Canister Vent on vehicles that do not have a separate EVAP Canister Vent

The LDP is a vacuum-driven, ECM controlled, diaphragm pump. In order to operate, the engine must be running and vacuum applied to the Vacuum Switch.