Chevrolet Equinox Service Manual: Transmission Adaptive Functions Automatic Transmission Unit

The 6T70/75 transmission utilizes a line pressure controlsystem during upshifts to compensate for the normal wear oftransmission components. As the apply components within thetransmission wear or change over time, shift time (the timerequired to apply a clutch) increase or decreases. In order tocompensate for these changes, the transmission controlmodule-(TCM) adjusts the pressure commands to thevarious PC solenoids, to maintain the originally calibrated shifttiming. The automatic adjusting process is referred to as“adaptive learning” and it is used to ensureconsistent shift feel plus increase transmission durability. TheTCM monitors the A/T input speed sensor-(ISS) and theA/T output speed sensor-(OSS) during commanded shifts todetermine if a shift is occurring too fast (harsh) or too slow(soft) and adjusts the corresponding pressurecontrol-(PC) solenoid signal to maintain the set shiftfeel.

The purpose of the adapt function is to automaticallycompensate the shift quality for the various vehicle shift controlsystems. The adapt function is a continuous process that will helpto maintain optimal shift quality throughout the life of thevehicle.