Patent ID: 6865965

Claim:
A hydraulic control system of an automated manual transmission having an input shaft with a plurality of drive gears, an output shaft with a plurality of driven gears engaging with the drive gears in accordance with drive conditions and to transmit power from an engine to a wheel drive shaft via the drive and driven gears, the transmission comprising: a shift actuator for shifting a change gear array and for transmitting the power from the input shaft to the output shaft; a plurality of bypass clutches for coupling and for uncoupling a connection between the input shaft and the output shaft respectively; a plurality of electromagnetic valves provided in a plurality of hydraulic oil paths for guiding a hydraulic pressure from a hydraulic pressure supply portion to the respective bypass clutches to open and to close the corresponding hydraulic oil paths, respectively; a bypass valve provided in a bypass oil path for bypassing the respective hydraulic oil paths for opening the bypass oil path to maintain a current gear ratio when one of the plurality of electromagnetic valves that provide the hydraulic pressure to the respective bypass clutches are inoperative due to a failure in an electric system, wherein said output shaft is substantially parallel to and axially displaced from said input shaft; and a fail mode valve that allows the hydraulic pressure to be supplied to at least one of the plurality of bypass clutches to enable a reverse mode to be engaged when a reverse range is selected by an operation of a select lever during the failure in the electric system.