A shift control system rotates an actuator to allow a wall of a detent plate and a roller of a detent spring to contact each other and then detects the position of contact so as to detect the position of the wall of the detent plate. After the wall position is determined, the actuator is driven in the direction opposite to the wall until the actuator reaches a position located before the wall position and distant therefrom by a predetermined amount, in order to cancel flexure or extension of the detent spring that is caused when the detent spring is pushed against the wall of the detent plate. Accordingly, such a situation where the shift position is moved by the recovery force of the detent spring can be avoided.