Engine Drag Torque Control (EDTC) is a system that applies additional torque (turning power) to wheels when needed to keep them rotating in order to prevent the car from sliding.
When a driver changes down a gear quickly, or takes their foot off the accelerator suddenly, the air pressure inside the engine changes which causes something called “engine braking” which slows the car down.
If the car slows down too suddenly then the wheels might lock up and start to slide.