An agricultural vehicle includes an engine, a transmission driven by the engine, and a controller. The controller, in operation, adjusts a gear ratio of the transmission using an algorithm. The algorithm, in operation, performs the following steps: reduce a torque capacity of a first offgoing clutch of the transmission to a first torque target, reduce the torque capacity of the first offgoing clutch to a second torque target while adjusting the torque capacity of a first oncoming clutch of the transmission to a third torque target, such that the gear ratio of the transmission is modified in a first direction, and increase the torque capacity of the first oncoming clutch to a desired torque capacity.

Disclosed are a method and an apparatus for controlling a damper clutch to prevent engine stall, and more particularly, to a method and an apparatus for controlling a damper clutch to prevent engine stall which can decide and correct when there is any error in control of a damper clutch in order to prevent engine stall. The method and the apparatus for controlling the damper clutch can decide and correct that a control unit of a damper clutch controller shows a wrong duty command value or a wrong current command value, thereby preventing engine stall, restraining decrease of acceleration power and blocking generation of noise or vibration.

A control system (44) for a clutch (18) of a manual transmission (16) in a vehicle (10) having an ECU (22), an engine (14), a pedal (26) having a sensor (42), a slave (34) in fluid communication with a master (36); and at least one input (24). The control system (44) includes a pump (50), a valve (52) in fluid communication with the slave (34) and pump (50), and a controller (46) responsive to the ECU (22) and operable in a plurality of modes for selectively cooperating with the pedal (26) to actuate the slave (34) and modulate the clutch (18) under predetermined engine (14) and vehicle (10) operating conditions. The controller (46) is movable between modes in response to signals from the ECU (22) representing predetermined changes in one or more of: engine speed, engine load, vehicle speed, transmission gear, pedal position, or input state.