TCS/ESP torque increase, general

When the drive wheels are rotating too slowly, TCS can request an increase in engine torque so that the wheels can regain their grip and thereby also course stability.

Fig 1: Engine Torque Graph (TCS/ECP)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Likewise, ESP can increase engine torque when the car is skidding in order to counter the skid.