Steuerungssystem für ein automatisches Getriebe mit Einrichtung zur manuellen Auswahl von Gängen

摘要

A multiple ratio automatic transmission control system for an automotive vehicle comprising a multiple ratio gear set and a simple planetary gear set arranged in series. The control system has multiple control modes including an automatic control mode in which upshifts and downshifts between adjacent ratios are achieved by engaging and releasing friction clutches and brakes in the simple planetary gear set and in the multiple ratio gear set and wherein a manual shift control mode includes a select-shift control. Engine braking is available in each gear for both operating modes. In the select-shift manual control mode, a particular gear can be chosen by the operator for continuous single ratio operation. The control system includes variable force solenoids that are multiplexed in combination with pressure modulator valves for achieving each operating mode.