A hydraulic control system for automatic transmission

A hydraulic control system for an automatic transmission, a plurality of hydraulic servo systems (53, 39, 45) for connecting and disconnecting a plurality of frictional engagement elements (B-1, B-2, B-3) and a control device (16, SL2) connecting the plurality of hydraulic servo systems (53, 39, 45) engaging pressure (B) supplies, a first switching valve (23) having a first terminal (x) to which an output pressure is supplied as the predetermined oil pressure from an oil pressure source, and a second terminal (m), wherein the first switching valve (23) is selectively positioned between a first position, wherein the first terminal (x) and the second terminal (m) are connected in a first switching stage, which is lower than a predetermined shift stage, so that the output pressure is output from the second terminal (m), and a second position in which the connection between the first terminal (x) and the second terminal (m) is interrupted in a second switching stage, which is different from the first switching stage, so that the output pressure from the second terminal (m) is not released; and a second switching valve (17) to a third terminal (b) connected to the second terminal (m) is connected to a fourth port (l), the output pressure is supplied without passing through the first switching valve (23), and a fifth terminal (k), the second switching valve (17) is selectively positioned between a first position in which the third port (b) and the fifth terminal (k) connected in the first switching stage and in a predetermined shift stage, so that the output pressure is supplied from the first switching valve (23), from the fifth terminal (k) is output, and a second position in which the fourth port (l) and the fifth terminal (k) in a switching stage than the second shift stage that is different from the predetermined switching stage, are connected, so that the output pressure from the fifth terminal (k) is delivered, wherein the control device (16) has a sixth port (j), which is connected to the fifth terminal (k), and a seventh terminal (g) that the output pressure is supplied to the sixth port (j), to the hydraulic servo system (53, 39, 45) as the engagement pressure (B) outputs, characterized in that the control device (16) serves to connect the seventh terminal (g) when a position of the second switching valve (17) is chosen selectively to the first position in the predetermined shift stage.