Shift control system for automatic transmission

摘要

A shift control system for an automatic transmission having an automatic shift mode in which a proper gear ratio is automatically selected according to a shift command based on a throttle valve opening and a vehicle speed, and further having a manual shift mode in which a gear ratio is selected according to a shift command given by driver's manual operation. The shift control system includes timer means for counting an elapsed time after a shift operation has been started. The elapsed time is compared with a predetermined first re-shift permission time in the case of automatic shift operation and with a predetermined second re-shift permission time in the case of manual shift operation. The first re-shift permission time and the second re-shift permission time are different from each other to optimize the shift control both in the automatic shift mode and in the manual shift mode.