Automatic transmission control system

摘要

An automatic transmission comprises a plurality of clutches 11 SIMILAR 15, which are provided to select power transmission paths, respectively, in a parallel shaft speed change mechanism TM and a plurality of shift valves 60 SIMILAR 68, which are used for controlling the supply and drain of hydraulic pressure to and from these clutches. For this automatic transmission, a control system comprises a forward/reverse selection hydraulic servomechanism 70 and a plurality of solenoid valves 81 SIMILAR 85, which are used for controlling the supply and drain of a line pressure so as to control the actuation of these shift valves and the forward/reverse selection hydraulic servomechanism. The system further comprises a hydraulic switch 93 which detects the hydraulic pressure supplied into the right side oil chamber 73 of the forward/reverse selection hydraulic servomechanism 70 and a hydraulic switch 92 which detects the hydraulic pressure of the SECOND speed clutch 12, whose pressure is generated from the pressure in the right side oil chamber 73. The system determines whether the forward drive range is set correctly or not, based on a result of pressure detection by these hydraulic switches 92 and 93. <IMAGE>