A vehicle having a device that uses an input provided from a first hydraulic system to charge one or more other hydraulic systems. The first hydraulic system can be a vehicle brake system or a hydraulic system having an electrically operated pump. The hydraulic systems to be charged could include an engine lubrication system and/or a transmission hydraulic control system.

Methods for controlling vacuum within a brake booster by modifying powertrain operation include determining an intake manifold vacuum in response to actuation of a brake pedal. Increasing the intake manifold vacuum if the brake booster vacuum is less than a desired brake booster vacuum. In some embodiments, the transmission is downshifted to increase engine speed and intake manifold vacuum.

A method and system for determining the pressure in a brake booster used to actuate a brake system having at least one main brake cylinder. The brake booster connected in a fluid-conducting manner by a non-return valve to an intake manifold of an internal combustion engine. A reduced pressure loss in the brake booster resulting from actuation of the main brake cylinder is balanced with the reduced pressure gain in the brake booster as a result of a pressure difference between the brake booster pressure and the intake manifold pressure. The reduced pressure gain in the brake booster is determined based on time the air mass flow between the brake booster and the intake manifold.

Disclosed herein is an idle stop control system including an information collection unit, a signal processing unit, and an engine control unit. The information collection unit collects information about idle stop control of an engine. The signal processing unit checks whether or not to satisfy a condition of idle stop control based on the information about idle stop control, and estimates a first cost loss incurred when a start-up state is maintained for an expected time of idle stop, and a second cost loss incurred during restart after the expected time of idle stop. The engine control unit controls an idle stop of the engine when the second cost loss is less than the first cost loss.

Methods for controlling vacuum within a brake booster by modifying powertrain operation include determining an intake manifold vacuum in response to actuation of a brake pedal. Increasing the intake manifold vacuum if the brake booster vacuum is less than a desired brake booster vacuum. In some embodiments, the transmission is downshifted to increase engine speed and intake manifold vacuum. In other embodiments, engine torque is reduced to increase intake manifold vacuum and the torque of the electric machine is increased to maintain a constant output torque.

A vehicle control apparatus assists a braking operation by using negative pressure in a negative pressure chamber generated by rotation of an internal combustion engine, automatically stops or restarts the engine if a first or second condition is satisfied, respectively. The apparatus determines whether a braking operation is performed, detects the rotational speed of the engine and the negative pressure in the negative pressure chamber using a negative pressure sensor. When a state has continued over a predetermined time while no braking operation has been detected, and the rotational speed has been over a threshold, the apparatus temporarily determine whether the sensor is abnormal, based on the negative pressure. When the sensor has been temporarily determined abnormal for a predetermined number of times, the abnormality is certainly determined to inhibit automatic stopping of the engine. The predetermined time may be changed depending whether the state has continued.

A control unit for a vehicle comprises an automatic engine stop-and-restart unit for stopping the engine responsive to predefined stop conditions and for restarting the engine responsive to predefined restart conditions, and a following-cruise control unit for controlling the vehicle to follow a vehicle ahead responsive to predefined following-cruise conditions. The automatic stop-and-restart unit for stopping and restarting the engine is configured to modify at least one of the stop conditions and the restart conditions during the following-cruise control.