| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device of an automatic transmission having a fail safe function for the case where a shift valve disposed in a hydraulic circuit sticks to be immobile, and a command change speed is not realized. SOLUTION: An automatic transmission includes a controller for previously string the correspondence relationship between the position of each shift valve 103-107 and the change speed realized at that time. For example, when a 3rd-4th shift valve 105 sticks to the elongation side of a spring and even if the control pressure is supplied to a control port 105a, the valve 105 is not moved to the contraction side of the spring, and in the case of a 4th speed change command, only the 3rd-4th clutch is put in the connecting state to disable a car from running, the condition where the 3rd-4th shift valve 105 sticks to the elongation side of the spring is deduced from the above correspondence relationship to inhibit a speed change command to the 4th speed. |
