Theory Of Operation
WARNING: This page is about a different car, the 2014 Fiat 500e. However, it is still accessible from the selected car via links, so may be relevant.
The A/C Shut Off Valve disables A/C cooling capability to the Cabin when cooling the High Voltage Battery is needed and cabin cooling is not, or when the High Voltage Battery needs full cooling capacity, the shut off valve shuts off cooling capability to the cabin, setting a DTC, and cools the High Voltage Battery only.