A quickshifter-equipped vehicle control unit includes an engine speed calculator configured to calculate an engine speed and a shift controller configured to operate in a quick shift mode and in a normal shift mode. The quick shift mode is a mode in which upon detection of the shift operation, the shift controller adjusts an output of an engine while keeping a main clutch in an engaged state, and the normal shift mode is a mode in which upon detection of the shift operation, the shift controller controls a clutch actuator to bring the main clutch into a disengaged state. The shift controller selects the quick shift mode when the engine speed is higher than a predetermined rotational speed threshold, and selects the normal shift mode when the engine speed is lower than the rotational speed threshold.

A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting the driving and driven pulleys. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes detecting a stall condition indicative of the vehicle being stalled, and, responsive to the detection, setting the piston force to be zero.

A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting the driving and driven pulleys. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes detecting a stall condition indicative of the vehicle being stalled, and, responsive to the detection, setting the piston force to be zero.

Control of a Vehicle Having an Automatic Transmission to Compensate for Ambient Air Density A method of controlling an automatic transmission (24) of a vehicle (10), the method comprising: receiving a signal indicative of a vehicle operating mode; obtaining a base map defining gear shift points for the transmission (24) based on the indicated vehicle operating mode; obtaining a torque loss map defining gear shift points for the transmission (24) based on a predetermined minimum value of density; and controlling the transmission (24) based on the base map if the base map defines gear shift points at higher engine speeds or vehicle speeds than the corresponding gear shift points defined by the torque loss map.

Control of a Vehicle Having an Automatic Transmission to Compensate for Ambient Air Density A method of controlling an automatic transmission (24) of a vehicle (10), the method comprising: receiving a signal indicative of a vehicle operating mode; obtaining a base map defining gear shift points for the transmission (24) based on the indicated vehicle operating mode; obtaining a torque loss map defining gear shift points for the transmission (24) based on a predetermined minimum value of density; and controlling the transmission (24) based on the base map if the base map defines gear shift points at higher engine speeds or vehicle speeds than the corresponding gear shift points defined by the torque loss map.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

A system for conducting a rationality check of a transmission grade sensor includes a controller configured to calculate a change in elevation over time based on a change in barometric pressure. The controller calculates another change in elevation based on an average grade determined from a transmission grade sensor. The controller compares the second change in elevation to the first change in elevation and, if there is a significant discrepancy between them, calculates a grade correction factor. The controller then modifies the shift logic and/or shift schedule of the transmission based on the average grade from the transmission grade sensor and on the grade correction factor.

A system for conducting a rationality check of a transmission grade sensor includes a controller configured to calculate a change in elevation over time based on a change in barometric pressure. The controller calculates another change in elevation based on an average grade determined from a transmission grade sensor. The controller compares the second change in elevation to the first change in elevation and, if there is a significant discrepancy between them, calculates a grade correction factor. The controller then modifies the shift logic and/or shift schedule of the transmission based on the average grade from the transmission grade sensor and on the grade correction factor.