A vehicle has an engine, a CVT and at least one ground engaging member. A method of controlling the engine includes the steps of: determining an idle speed set point based at least in part on a first speed proportional to a driven pulley speed, the idle speed set point being less than an engagement speed when the driven pulley speed is less than a predetermined driven pulley speed and being less than an actual engine speed when the driven pulley speed is greater than the predetermined driven pulley speed; and controlling the engine to operate under conditions corresponding to the idle speed set point when a desired engine speed is less than the idle speed set point. Controlling the engine to operate under conditions corresponding to the idle speed set point causes engine braking when the driven pulley speed is greater than the predetermined driven pulley speed.

Systems and methods for controlling engine brake disengagement in a vehicle include a controller receiving a signal indicative of a command to disengage an engine brake while the vehicle engine is in engine brake engaged condition. The engine can be subjected to a first negative torque under the engine brake engaged condition. The controller can cause the engine brake to be gradually disengaged over a time period using a predefined torque ramp rate, responsive to the signal. The gradual disengagement of the engine brake can be in the form of a phased out disengagement, and can reduce vehicle engine jerk associated with engine brake disengagement.

A braking force control device includes a target acceleration calculation unit that calculates a first target acceleration based on an acquired operation amount of an accelerator pedal, a powertrain capability acquisition unit that acquires a braking force that is generable by a powertrain, and an instruction unit that instructs generation of braking forces in the powertrain and a brake. The instruction unit is configured to, when a first braking force for achieving the first target acceleration is equal to or less than the braking force that is generable by the powertrain, instruct a controller of the powertrain to generate the first braking force, and when the first braking force is larger than the braking force that is generable by the powertrain, instruct the controller of the powertrain to generate the braking force that is generable by the powertrain.

A control device, system and method that distribute a braking request to at least one of a powertrain and a brake based on a braking request by driver operation and a braking force that is generable by the power train. When the braking request is larger than the braking force that is generable by the powertrain, the device, system and method instruct a controller of the powertrain to generate the braking force that is generable by the powertrain, and to instruct a controller of the brake to generate a braking force corresponding to a difference between the braking request and the braking force that is generable by the powertrain.

Systems and methods for controlling engine brake disengagement in a vehicle include a controller receiving a signal indicative of a command to disengage an engine brake while the vehicle engine is in engine brake engaged condition. The engine can be subjected to a first negative torque under the engine brake engaged condition. The controller can cause the engine brake to be gradually disengaged over a time period using a predefined torque ramp rate, responsive to the signal. The gradual disengagement of the engine brake can be in the form of a phased out disengagement, and can reduce vehicle engine jerk associated with engine brake disengagement.

Methods and systems are provided for improving fuel economy and reducing undesired emissions. In one example, a method may include in response to an engine speed being within a first threshold speed of an engine idle speed during a speed reduction request with engine cylinders unfueled, maintaining the cylinders unfueled, and controlling the engine to a desired stopping position responsive to the engine speed being greater than a second threshold speed lower than the idle speed. In this way, fuel usage and emissions may be reduced and engine restart requests may be conducted at least in part via vehicle inertia.

Methods and systems are provided for improving fuel economy and reducing undesired emissions. In one example, a method may include in response to an engine speed being within a first threshold speed of an engine idle speed during a speed reduction request with engine cylinders unfueled, maintaining the cylinders unfueled, and controlling the engine to a desired stopping position responsive to the engine speed being greater than a second threshold speed lower than the idle speed. In this way, fuel usage and emissions may be reduced and engine restart requests may be conducted at least in part via vehicle inertia.

A braking force control device includes a target acceleration calculation unit that calculates a first target acceleration based on an acquired operation amount of an accelerator pedal, a powertrain capability acquisition unit that acquires a braking force that is generable by a powertrain, and an instruction unit that instructs generation of braking forces in the powertrain and a brake. The instruction unit is configured to, when a first braking force for achieving the first target acceleration is equal to or less than the braking force that is generable by the powertrain, instruct a controller of the powertrain to generate the first braking force, and when the first braking force is larger than the braking force that is generable by the powertrain, instruct the controller of the powertrain to generate the braking force that is generable by the powertrain.

A braking force control device includes a target acceleration calculation unit that calculates a first target acceleration based on an acquired operation amount of an accelerator pedal, a powertrain capability acquisition unit that acquires a braking force that is generable by a powertrain, and an instruction unit that instructs generation of braking forces in the powertrain and a brake. The instruction unit is configured to, when a first braking force for achieving the first target acceleration is equal to or less than the braking force that is generable by the powertrain, instruct a controller of the powertrain to generate the first braking force, and when the first braking force is larger than the braking force that is generable by the powertrain, instruct the controller of the powertrain to generate the braking force that is generable by the powertrain.

A method for controlling an internal combustion engine of a vehicle having a continuously variable transmission is disclosed. When a driven pulley speed is less than a predetermined driven pulley speed and an actual engine speed is less than an engine speed causing a driving pulley speed to be a driving pulley engagement speed: controlling the engine to increase the actual engine speed to increase the driving pulley speed to be at least the driving pulley engagement speed. When the driven pulley speed is above the predetermined driven pulley speed, the actual engine speed is greater than the engine speed causing the driving pulley speed to be the driving pulley engagement speed, and the desired engine speed is less than the engine speed causing the driving pulley speed to be the driving pulley engagement speed: controlling the engine to operate under conditions corresponding to an engine braking speed.