HDC

📖 YOUCANIC Automotive Glossary

HDC (Hill Descent Control) is a driver-assist feature on SUVs and off-road vehicles that automatically maintains a slow, controlled speed (typically 3-15 MPH, adjustable by the driver) when descending steep grades without the driver touching the brake pedal. HDC uses the ABS system to individually pulse the brakes on each wheel, preventing wheel lockup while maintaining a crawl speed. The system is activated by a dashboard button and typically operates only at low speeds in a low gear range. HDC is invaluable for steep off-road descents, boat ramp approaches, and icy downhill parking structures where maintaining control without wheel lockup is critical.

HDC faults are diagnosed through the ABS/ESC module since it uses the same hardware. Conditions that disable HDC include ABS faults, ESC faults, overheated brakes (the system generates significant brake heat during extended descents), and vehicle speed above the operating threshold. The YOUCANIC UCAN-II reads ABS/ESC codes affecting HDC operation.