PURPOSE: To correctly set the neutral position of a shift actuator and the shift position in each speed change stage by performing renewal by using the detection value of a stroke sensor in the operation of a shift actuator to a neutral state, as learned value.

CONSTITUTION: The shift quantity of a shift actuator 1 in the operation to a neutral stage is detected by a stroke sensor 4, and the aimed shift value is renewed by using the detected shift value as the learned value, and the aimed shift value in the neutral stage is set. When the aimed shift value in each speed change stage is set, setting is performed by adding the offset value onto the aimed shift value in the neutral stage as standard. The time after the lapse of the prescribed time set in the shift operation is considered as the completion of the shift operation. Since the shift position is renewed and set by using the value detected by the stroke sensor 4 as the leaned value, the neutral position as standard can be correctly set without using the torublesome adjusting process.