Left Rear FOOTWELL Vent Temperature Sensor -G637-, Removing And Installing: Notes
WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
The Left Rear Footwell Vent Temperature Sensor -G637- is only installed on a vehicle with a "High" A/C system. On a vehicle with a "Low" A/C system (or with a heater and A/C system) the installation opening if the air duct can be open or closed.