Hill-Descent Control
Hill-descent control (HDC) helps maintain a low, controlled speed on a steep downhill section without the driver continuously operating the brake pedal. It is mainly intended for loose, uneven, or off-road surfaces.
What it does
When enabled within its operating range, HDC uses individual wheel braking and may coordinate drive or regenerative torque to hold a target speed. The driver normally steers and can often adjust the target with pedals or cruise-control switches. Availability, speed range, supported gears, and behavior differ by vehicle.
HDC cannot create tire grip and does not choose a safe route. Ice, loose stones, deep ruts, excessive speed, brake temperature, and a gradient outside the supported range can reduce control or disable the function. It is distinct from hill-start assist, which briefly holds a stationary vehicle while the driver begins moving uphill.
For the shared brake-control hardware and stability functions, see Electronic Stability Control.