Reducing braking torque instead of engine torque to accelerate vehicle during vehicle hill descent control

Abstract

A vehicle hill descent control system and method for controlling a vehicle during a hill descent receives inputs from an accelerator pedal position sensor and a brake pedal sensor. The method controls the engine drivetrain system to engine idling and controls the braking control system to maintain vehicle speed by increasing braking torque to minimize or offset a vehicle speed increase due to gravity. In vehicle hill descent mode, when a vehicle user actuates the accelerator pedal, the engine idling does not change. Instead, the electronic control unit operates to decrease braking torque so the vehicle speed is increased.