3023615 - E7022 VDC - Description

Description

The electronic anti-lock brake system (BOSCH 5.7 ABS with ASR) governs braking pressure sent to the wheels and prevents loss of grip under all tyre and road surface conditions.This is combined with a VDC (VEHICLE DYNAMIC CONTROL) system, which controls vehicle stability by modulating drive torque and braking the wheels differentially, if there is a loss of grip, thus helping to return the car to its correct trajectory.The VDC system acts on the engine and brakes to generate a stabilising torque when the ABS sensors detect conditions that could lead to the vehicle slipping.

The VDC system includes the following specific components over and above those of the ABS:

• a sensor which detects the steering wheel position (steering sensor);
• a sensor which detects the vehicle's rotation around the vertical axis and side acceleration (centrifugal force) (yaw sensor);
• a sensor that detects pressure on the hydraulic ABS unit (pressure sensor)

By processing information from the sensors, the control unit is able to find out car position moment by moment and compare the position with the driver's ideal trajectory. If the values do not tally, within a fraction of a second the control unit chooses and implements more effective actions to restore the vehicle to its trajectory immediately: it applies a braking force of different intensity to one or more wheels and reduces power transmitted by the engine if necessary.The VDC comes on automatically when the vehicle is started up and cannot be switched off.A warning light on the control panel flashes when the system cuts in to notify the driver that the VDC system has come on.When the control unit detects an error in the VDC function, the warning light is made to stay on in fixed mode.

the same warning light is also used for the ASR function; The VDC systems is connected to the ASR system  See E7021  ASR / TCS .