US Patent 9316311 Method and apparatus for controlling a shift-by-wire transmission

A method of controlling a shift-by-wire transmission is provided. The method monitors a setting of a shift assembly that sets a select gear from gearing of the transmission. A motor is activated to adjust the setting of the shift assembly when the monitoring of the shift assembly indicates that the then current setting of the shift assembly is outside of a course window of a desired gear. The course adjustment window is centered about a nominal target position for the desired gear while being within an acceptable range of the select gear. The motor is shut off when the monitoring of the setting of the shift assembly indicates the setting is within a fine adjustment window of the desired gear. The fine adjustment window is also centered about the nominal target position for the desired gear. The fine adjustment window is narrower than the course adjustment window.