Regulating The Solenoids When GEARSHIFTING

Gearshifts are regulated by means of the Transmission Control Module (TCM) activating the solenoids in specific patterns. The solenoids S1, S2, SLC1, SLC2, SLC3 and SLB1 control which gear shall be engaged. The solenoids SLC1, SLC2, SLC3 together with solenoid SLT also control how the engagement shall take place by means of adapting the hydraulic pressure. The basic parameters for the differences in gearshift timing are the position of the accelerator pedal and vehicle speed, while the gearshift quality is determined by the torque steer.

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).

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