Systems and methods for controlling transmissions having CVTs are disclosed with multiple modes and gearing arrangements for range enhancements, where embodiments include synchronous shifting to allow the transmission to achieve a continuous range of transmission ratios, while minimizing empty cycling of the CVT during mode shifts. Embodiments provide for wide ratio range and performance and efficiency flexibility, while maximizing CVT usage through synchronous shifting.

A shift-by-wire transmission system is provided. The system includes a gearbox that is configured and arranged to receive a rotational input and provide a select rotational output. The gearbox includes a plurality of gear assemblies that are operationally coupled together to provide the select rotational output from the rotational input. A shift assembly is operationally coupled to the plurality of gear assemblies of the gearbox to selectively change gearing of gearbox. An electric motor is operationally coupled to the shift assembly to activate the shift assembly to selectively change the gearing of the gearbox. A manual shift override is employed that is coupled between the shift assembly and the electric motor. The manual shift override is configured and arranged to manually disconnect the electric motor from the shift assembly and activate the shift assembly.

A method for shifting a marine propulsion device transmission between first and second gears transmitting torque from a powerhead with a redline RPM. The transmission has a transition time for completing a shift. The method includes measuring an RPM of the powerhead, comparing the RPM to a first threshold, and starting a timer when the RPM exceeds the first threshold. The method includes measuring the RPM of the powerhead after the first threshold is exceeded, comparing the RPM to a second threshold, stopping the timer when the RPM exceeds the second threshold, determining an elapsed time between starting and stopping the timer, and determining a shift RPM based on the determined elapsed time, the redline RPM, and the transition time of the transmission. The method includes controlling the transmission to shift when the RPM measured for the powerhead reaches the shift RPM such that shifting completes before the redline RPM.

Systems and methods for controlling transmissions having CVTs are disclosed with multiple modes and gearing arrangements for range enhancements, where embodiments include synchronous shifting to allow the transmission to achieve a continuous range of transmission ratios, while minimizing empty cycling of the CVT during mode shifts. Embodiments provide for wide ratio range and performance and efficiency flexibility, while maximizing CVT usage through synchronous shifting.