Engine Coolant Temperature Sensor On Radiator Outlet - G83-, Checking: General Description
WARNING: This page is about a different car, the 2018 Audi A3 Quattro, 2017 Audi A3 Quattro, 2016 Audi A3 Quattro, 2016 Audi A3, and 2015 Audi A3 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
The Engine Coolant Temperature Sensor On Radiator Outlet -G83- sends information about the current coolant temperature to the Engine Control Module -J623-. It uses the coolant temperature as a correction value for calculating the injection quantity.