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, SL1, SL2, SL3, SL4 and SL5 control which gear shall be engaged. The solenoids SL1, SL2, SL3, SL4 and SL5 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 shifting takes place at relatively low rpm to reduce fuel consumption. At higher acceleration/throttle Transmission control module (TCM) automatically switches to another shifting program. These shifting programs are based on engine type.