Oil pressure control system for automatic transmission

摘要

An oil pressure control system for an automatic transmission for executing a downshift by disengaging a first frictional engagement element and engaging a second frictional engagement element. At a latter stage of a shift, the first frictional engagement element has its torque capacity increased by raising its oil pressure temporarily. After this, if a synchronization substantially reaching the revolution number at a gear stage after the downshift is detected, the first frictional engagement element has its torque capacity gradually dropped by dropping the oil pressure thereof gradually, and the second frictional engagement element has its oil pressure abruptly raised.