Hill Descent Control

How Hill Descent Control system works in a car?


What is Hill Descent Control in cars?

Hill Descent Control (commonly abbreviated as HDC) is a driver assistance system provided mainly on all-wheel-drive off-roading vehicles such as SUVs. This system comes into play when the vehicle is coasting down a steep slope.

Working Of Hill Descent Control (HDC):

Hill Descent Control (Image Courtesy: Mitsubishi)
Hill Descent Control (Image Courtesy: Mitsubishi)

Usually, it is observed that drivers find it difficult to control the vehicle while descending down a steep or sharp slope because they have to critically pay attention to both the steering and the braking of the vehicle. Thus, there is a high probability that the vehicle may go out of control. Engineers invented the Hill Descent Control system to avoid such situation.



The main function of the HDC system is to help the driver while traveling down a sharp slope. It does so by limiting the speed of the vehicle to a predetermined value. This allows the driver to concentrate only on the steering. Thus, the driver achieves better control of the vehicle. You can activate the HDC merely by pressing the button. After that, it reduces the vehicle speed to the predetermined speed without any brake input from the driver.

HDC button on dashboard (Image Courtesy: Volvo)
HDC button on dashboard (Image Courtesy: Volvo)

Some of the modern HDC systems allow the driver to set the speed limit by using ‘Cruise control’ function while others don’t have this facility. Hill Descent Control works in unison with the ABS of the vehicle and thus monitors the speed of each wheel individually avoiding the possibility of wheel lock.



HDC system is useful, especially while traveling on the loose and slippery roads such as snow or gravel covered roads. HDC system gets deactivated when the driver presses either the accelerator or the brake pedal.

For some more information on the HDC technology, please click here.

Watch Hill Descent Control in action here:

Read More: What is Hill Start Assist in cars?>>

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