Air Conditioning (A/C) Recirculation Switch
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The A/C recirculation switch circuit provides a voltage signal to the PCM which indicates the A/C recirculation mode is requested. The PCM requests the traction battery cooling system to enter the recirculation mode when the PCM receives the A/C recirculation signal.