Reverse Flushing
WARNING: This page is about a different car, the 2023 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
Reverse flushing of the cooling system is the forcing of water through the cooling system. This is done using air pressure in the opposite direction of normal coolant flow. It is usually only necessary with very dirty systems with evidence of partial plugging.