Hill Descent Control
H i l l D e s c e n t C o n t r o l H I L L D E S C E N T C O N T R O L
Hill Descent Control in action During a descent, if engine braking is insufficient to control the vehicle speed, HDC (if selected) automatically operates the brakes to slow the vehicle and maintain a speed relative to the selected gear and the accelerator pedal position.
When driving off-road, HDC can be permanently selected, to ensure that control is maintained whenever low range gears are engaged. ABS and traction control are still fully operational and will assist if the need arises.
NOTE: With HDC selected, gear changes can be carried out in the normal way.
Hill Descent Control (HDC) operates in conjunction with the anti-lock braking system to provide greater control in off-road situations particularly when descending severe gradients.
If the brake pedal is depressed when HDC is active, HDC is overridden and the brakes will perform as normal (a pulsation might be felt through the brake pedal). If the brake pedal is then released, HDC will recommence operating if necessary.
To select HDC HDC can be selected with the vehicle in any gear, but will only operate when the transfer gearbox is in low range, gears are engaged with the vehicle travelling at less than 31 mph (50 km/h).
Press the switch (illustrated above) to select HDC.
If low range gears are engaged, the HDC information light (GREEN) on the instrument panel will illuminate (if low range gears have NOT been selected, the light will flash and the warning chime will sound continuously).
In extreme circumstances, the HDC system may cause brake temperatures to exceed their pre-set limits. If this occurs, the HDC ‘failure’ warning light (AMBER) will start to flash and the warning chime will sound continuously. During this time HDC will function as normal.
To avoid further cause for brake temperatures to rise, engage an appropriate low gear for steep descents and avoid descending hills at higher than the minimum descent speed. If the ‘failure’ amber warning light continues to flash, the HDC system will gradually fade out (see ‘HDC fade-out’, page 139) and the HDC information light may extinguish.
To deselect HDC, press the switch a second time (the information light will extinguish and a single warning sound will chime).