CONTROL SYSTEM AND CONTROL METHOD FOR AUTOMATIC TRANSMISSION

摘要

In case shifting frictional engagement elements are kept in engaging states by the output oil pressure of a normal close type linear solenoid valve, an ECU calculates (at S102) a necessary oil pressure (PR) for each frictional engagement element kept in the engaging state. The ECU calculates (at S106) the maximum pressure of the necessary oil pressures (PR) as a target command pressure (P) for each frictional engagement element, calculates (at S108) a drive current (I) on the basis of the target command pressure (P) calculated, and outputs (at S110) the calculated drive current (I) to each linear solenoid valve. The ECU calculates the necessary oil pressure (PR) as a value larger than the minimum pressure necessary for keeping each frictional engagement element in the engaging state and smaller than the maximum pressure (P(MAX)) of the target command pressure (P).