When a vehicle electric power source is turned on, and when a target mode position is other than a parking (P)-mode position and a driving (D)-mode position or the target mode position is unfixed, a shift-by-wire electronic control unit (SBW-ECU) does not drive the actuator so that the current actual mode position is maintained. The SBW-ECU accepts only the driver's requirement for changing the mode position to the P-mode position or the D-mode position. When it is required to change the mode position to the P-mode position, a first position learning portion learns a first reference position. When it is required to change the mode position to the D-mode position, a second position learning portion learns a second reference position.