Controlling Shift Solenoids When Shifting

The solenoids are activated in a specific pattern to control shifting and the lock-up function. Solenoids S1-S5 determine which gear is to be used. Solenoids SLS, SLU and SLT determine engagement by adjusting the hydraulic line pressure. The basic parameters for the different shifting points are the accelerator pedal (AP) position and the vehicle speed. The shift quality is decided by controlling the torque.

The pressurization of the clutches and the brakes is adjusted by reading the changes in speed of the transmission input shaft during the shifting process and comparing them to the values calculated in the transmission control module (TCM).

Two different shift patterns are available: normal mode and winter mode (selected using the "W" button).

In normal conditions, shifting and lock-up occur at relatively low engine speeds to reduce fuel consumption. In the event of rapid accelerator pedal movements, the transmission control module (TCM) automatically shifts to sport mode.