Hill Descent Control
From DISCO4.COM Knowledge Base
Hill Descent Control (HDC) is a system used on the Discovery 3 (and other vehicles), allowing a controlled method of moving down slippery inclines. It works by sensing the traction level at each wheel, and adjusting the braking force applied at each corner by automatic application of braking by the Antilock Braking System (ABS). Once descent begins, vehicle speed can be controlled by use of the steering wheel cruise control speed adjusters to maintain a steady descent.
The system is either automatically selected in certain Terrain Response modes, or is manually activated via the yellow button on the Terrain Response switchgear.
The HDC state is shown on the dashboard display and premium satellite navigation screen, if fitted.