Hill Descent Control (HDC)

WARNING: This page is about a different car, the 2000 Land Rover Discovery and 1999 Land Rover Discovery. However, it is still accessible from the selected car via links, so may be relevant.

HDC is selected by an on/off switch on instrument panel. When in HDC mode, driver can control vehicle's downhill speed using only the accelerator pedal. HDC is enabled in all forward gears and reverse when vehicle speed is less than 31 MPH, transfer box is in low range, and clutch is engaged (if equipped with M/T).

SLABS ECU determines vehicle target speed from throttle position and gear selection. If engine braking is insufficient to control vehicle speed, HDC automatically operates brakes to slow vehicle. While HDC is slowing vehicle down, SLABS ECU energizes brake light relay to turn brakelights on. HDC is discontinued if vehicle speed drops below target speed or brakes are applied. SLABS ECU will fade out HDC if a fault is detected, HDC conditions are no longer met or brakes are starting to overheat.