Downhill traction control HDC
Car device

Downhill traction control HDC

28.06.2022 /

Downhill traction control HDCOne of the active safety systems is the Hill Descent Assist (HDC) function. Its main task is to prevent an increase in the speed of the machine and to provide controllability when driving downhill.

The main scope of HDC is off-road vehicles, that is, crossovers and SUVs. The system improves the quality of vehicle handling and increases the degree of safety when descending on high-altitude roads and off-road.

The HDC system was developed by Volkswagen and is currently actively used on many models of the German manufacturer. In terms of its functionality, the system is a logical continuation of the exchange rate stability (EBD) system. There are several different Volkswagen models in FAVORIT MOTORS Group of Companies, which allows you to choose the best car option for each driver.

Principle of operation

Downhill traction control HDCThe action of HDC is based on providing a stable speed during the descent due to the constant braking of the wheels by the engine and brake system. For the convenience of the driver, the system can be turned on or off at any time. If the switch is in the activated state, then HDC is activated in automatic mode with the following indicators:

  • the vehicle is in a running state;
  • the driver does not hold the gas and brake pedals;
  • the car moves by inertia at a speed not exceeding 20 kilometers per hour;
  • the slope angle exceeds 20 percent.

Information about the speed of movement and the beginning of a steep descent is read by various sensors. The data is sent to the electric control unit, which activates the reverse hydraulic pump functionality, as well as Downhill traction control HDCcloses intake valves and high pressure valves. Due to this, the braking system provides the level of pressure that can reduce the speed of the car to the desired value. In this case, the speed value will be determined depending on the already existing machine speed and the gear engaged.

Once a certain wheel speed has been reached, forced braking will be completed. If the vehicle starts accelerating again due to inertia, the HDC hill descent control system will be activated again. This allows you to maintain a constant value of the safe speed and vehicle stability.

It should be noted that after climbing a descent, HDC will turn itself off as soon as the slope is less than 12 percent. If desired, the driver can turn off the system himself - just press the switch or press the gas or brake pedal.

The advantages of using

Downhill traction control HDCA car equipped with HDC feels great not only on descents. This system allows the driver to focus on steering only when driving off-road or in mixed terrain. In this case, it is not necessary to use the brake pedal, as the HDC regulates safe braking on its own. The traction control system allows you to drive in both the "forward" and "backward" directions, while in both cases the brake lights will be on.

HDC works in conjunction with the ABS system and in active interaction with the mechanisms that regulate the operation of the propulsion unit. Traffic safety is achieved through the use of sensors of adjacent systems and the provision of integrated braking.

FAVORIT MOTORS specialists offer their competent services in case of need to correct the operation or replace one of the elements of the HDC system. Procedures of any complexity are performed using professional diagnostic equipment and narrow-profile tools, which guarantees the impeccable quality of the work performed.

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