Hill Descent Control (HDC)

A system pioneered by Land Rover's Freelander, and now used by a number of other 4x4s under a range of different names. HDC allows a smooth and controlled hill descent in rough terrain without the driver needing to touch the brake pedal. The system uses the anti-lock brakes to hold a low speed while keeping the wheels turning, even on steep or slippery slopes. If the vehicle starts to accelerate without driver input, the system automatically applies the brakes to slow down to the desired vehicle speed. The HDC system does away with the need for a low-ratio transfer gearbox.