Control system for automatic vehicle transmission

摘要

A system for controlling an automatic transmission mounted on a vehicle, including a gear system and hydraulic clutches which hold a member of the gear system stationary to produce gear reduction or reverse to transmit engine output, and a linear solenoid valve provided in the oil line which generates an oil pressure to be supplied to hydraulic clutches in response to a current supplied thereto. In the system, the current supply is initiated when the ignition switch is turned to the ON position where the engine is not started, producing a noise due to the solenoid valve operation. In order to avoid this, the current is limited to a predetermined value when the engine is not started and the vehicle is stopped. Moreover, since the predetermined value is slightly above the current at which the clutch pressure begins to rise, the automatic transmission can start its operation quickly when the engine is started.