Abstract: A power transmission apparatus includes a continuously variable transmission, a clutch, a drive condition determination device, an input torque calculator, a belt transfer torque calculator, and a clutch transfer torque controller. The continuously variable transmission includes a drive pulley, a driven pulley, and a belt. The clutch transfer torque controller controls a transfer torque of the clutch so that the transfer torque of the clutch is higher than or equal to an input torque calculated by the input torque calculator and is lower than a transfer torque of the belt calculated by the belt transfer torque calculator if it is determined that the vehicle is under a drive condition.

Abstract: A control system for a vehicle includes an engine switch control unit for switching the operating condition of the engine between the all-cylinder operating condition and the partial-cylinder operating condition, a failure determining unit for determining the failure of the lockup clutch control device, and a coupling capacity change inhibiting unit for inhibiting a change in coupling capacity of the lockup clutch accompanied by the switch control of the operating condition of the engine by the engine switch control unit during the failure determination by the failure determining unit.

Abstract: In a system for controlling an internal combustion engine having a plurality of cylinders and connected to the automatic transmission and mounted on a vehicle and the operation of the engine is switched between full-cylinder operation during which all of the cylinders are operative and cutoff-cylinder operation during which some of the cylinders are non-operative, based on at least the load of the engine, a gradient of road on which the vehicle runs is estimated and the cutoff-cylinder operation is prohibited when the estimated gradient is equal to or greater than a threshold value. With this, it becomes possible to generate sufficient deceleration, when the vehicle runs a downhill during cutoff-cylinder operation, while ensuring to prevent the operator to feel excessive acceleration.

Abstract: A control system for a vehicle having an engine with a plurality of cylinders whose operating condition is switchable between an all-cylinder operating condition where all of the cylinders are operated and a partial-cylinder operating condition where a part of the cylinders is operated according to an operating condition of the vehicle, a torque converter with a lockup clutch connected to the engine, and a lockup clutch control device for controlling the lockup clutch.

Abstract: In a system for controlling an internal combustion engine having a plurality of cylinders and connected to the automatic transmission and mounted on a vehicle and the operation of the engine is switched between full-cylinder operation during which all of the cylinders are operative and cutoff-cylinder operation during which some of the cylinders are non-operative, based on at least the load of the engine, a gradient of road on which the vehicle runs is estimated and the cutoff-cylinder operation is prohibited when the estimated gradient is equal to or greater than a threshold value. With this, it becomes possible to generate sufficient deceleration, when the vehicle runs a downhill during cutoff-cylinder operation, while ensuring to prevent the operator to feel excessive acceleration.