third and fourth speeds the second clutch c 2 receives hydraulic pressure through the second pressure control valve 106 and the second switch valve 108 in the third and fourth speeds and the third clutch c 3 receives control pressure of the fourth pressure control valve 114 in the reverse r range also the fourth clutch c 4 according to control by the first switch valve 104 receives line pressure in the park p reverse r and neutral n ranges and output pressure of the first pressure control valve 102 in the second third and fourth speeds the first brake b 1 receives hydraulic pressure directly from the manual valve 100 in the reverse r range and in the low l range receives hydraulic pressure through the second pressure control valve 106 and the second switch valve 108 the second brake b 2 receives hydraulic pressure through the third pressure control valve 110 and the fail safe valve 112 in the second and fourth speeds in the hydraulic control system of the present invention described above exceptional non synchronous control by the one way clutches is realized fast shift response times are obtained and hydraulic pressure control of the first friction element by the solenoid valves is effected to enable control into neutral when idling such that fuel consumption is minimized further with the good independent control a high quality of shifting is realized also the number of solenoid valves is reduced by realizing control of the six friction elements by the four solenoid valves finally since shifting into four speeds is realized by two one way clutches the advantages of one way clutches are.