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.

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.

Disclosed are a control method for a hydraulic retarder, and a control system. The method includes: acquiring a slope of a downhill road segment ahead of a vehicle; determining whether an absolute value of the slope is greater than an absolute value of a slope for which a braking force is not required; if so, predicting a required braking force and oil amount for the vehicle at a steady speed; predicting, according to the oil amount, oil filling time and a distance between the vehicle and an origin of the above road segment at the start time of oil filling of the hydraulic retarder; in the case that the actual distance of the vehicle is equal to a predicted distance, starting oil filling; and upon the vehicle reaching the origin of the road segment, starting braking. The present disclosure can lower wear of brake pads and reduce vehicle running costs.

Presented are vehicle display systems for generating digital window stickers that enable connected vehicle applications, methods for making/using such display systems, and vehicles equipped with such display systems. A method of operating a vehicle display system includes a passenger cabin telematics unit receiving a selection from a vehicle occupant to execute a desired transaction with a principal party. Upon receiving the occupant's selection, the telematics unit responsively selects a digital window sticker with a virtual barcode for completing the desired transaction. The telematics unit also responds to receiving the occupant's selection by determining a real-time location of the host vehicle, and determining when the host vehicle has completed a predefined dynamic vehicle action. Upon confirming the vehicle completed the dynamic vehicle action and the vehicle's real-time location is within a predefined proximity to the principal party, the vehicle display system displays the digital window sticker in the occupant side window.