Regulating the solenoids when gearshifting

Shifting is regulated by the transmission control module (TCM) activating the solenoids in a specific pattern. The solenoids control which gear is engaged. The solenoids also control how engagement occurs by adapting hydraulic pressure. The basic parameters for the various shift points are accelerator pedal position and vehicle speed while shift quality is determined by torque control.

The pressurizing of clutches and brakes can be adapted by means of reading off the changes in the rotation speed of the transmission input shaft during the gearshift processes and comparing them with the calculated values in the Transmission Control Module (TCM).

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

In normal conditions the gearshifts take place at relatively low speeds in order to reduce fuel consumption. With rapid accelerator pedal movements the Transmission Control Module (TCM) automatically changes over to sport mode.

^*) with engine braking