Controlling The Shift Solenoids When Shifting

The solenoids are activated in a specific pattern to control shifting and the lock-up function. Solenoids S1 and S2 determine which gear is to be used at the time. Solenoids SL and STH determine engagement by adjusting the hydraulic line pressure of the transmission. The basic parameters for the different shifting points are the accelerator pedal (AP) position and the vehicle speed. The shift quality is decided by the control of torque and pressure control of the STH solenoid.

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

Two shifting patterns can be selected, normal conditions and winter mode (selected using the button).

In normal mode 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.

Shifting patterns