| 摘要 |
PURPOSE: A method for controlling a power off downshift operation from third to second ranges is provided to reduce a sudden torque change through supplying optimum hydraulic pressure to a kick-down servo, and to improve shift quality through changing stopping condition of a shift control. CONSTITUTION: A shift control instrument decides an output of a power off downshift operation control signal from third to second ranges. The instrument decides off state of a kick-down switch deciding operation point of a kick-down band for operating a fill time. After establishing a duty inclination as S1, a corresponding duty control signal is outputted to a driving instrument. The shift control instrument decides satisfaction of a shift synchronizing condition for downshifting. The duty inclination is established as S2 for outputting a corresponding duty control signal to the driving instrument. A tip shift control instrument decides an output of a power on signal for establishing a new duty value. The control instrument decides the duty inclination as S5 for outputting the duty control signal to the driving instrument. The control instrument decides completion of a shift synchronization.
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