Shift controller for vehicle

A shift controller for a vehicle, comprising:

• a shift switching unit configured to switch a shift position of the vehicle to one of a plurality of shift positions by driving an actuator which is supplied with power from a power supply;
• a rotation restricting element configured to restrict rotation of the actuator in a predetermined direction at a predetermined shift position among the plurality of shift positions;
• and
• an electronic control unit configured to
• acquire a count value corresponding to a degree of rotation of the actuator,
• set a rotational position of the actuator when the count value does not change by restricting rotation of the actuator using the rotation restricting element as a reference position of the actuator corresponding to the predetermined shift position, and
• interrupt setting the reference position of the actuator and restart setting the reference position of the actuator when the following conditions (1) and (2) are met:
• (1) the rotation of the actuator is restricted by the rotation restricting element and (2) either (a) a supply voltage to the actuator is equal to or lower than a predetermined first voltage determination value or (b) a variation in the count value while the rotation of the actuator is restricted by the rotation restricting element is equal to or greater than a predetermined value.