COLLISION PREVENTION ASSIST, a component of the Driving Assistance package, warns the driver actively if the distance to the vehicle ahead is insufficient, as well as providing support in an emergency braking manoeuvre.
It combines a radar-based proximity warning function with the braking force boost of the Braking Assist system, thus helping to reduce the danger of a rear-end collision. The COLLISION PREVENTION ASSIST proximity warning system is based on a mid-range radar sensor installed in the vehicle front and which monitors the relative velocity and the distance to the vehicle directly ahead; it is constantly active in the speed range from 30 to 160 km/h. Stationary obstacles can be registered when the vehicle is moving at a speed of up to 70 km/h.
If the safety distance to a vehicle travelling ahead is undercut for several seconds, a waning lamp lights up in the instrument cluster. If the distance continues to diminish rapidly due to the vehicle's high speed or strong acceleration, an intermittent warning is additionally sounded. At the same time COLLISION PREVENTION ASSIST activates the BAS pro Braking Assist system. This system then calculates the braking pressure required to avoid a rear-end collision. If the driver now depresses the brake pedal with force, BAS pro automatically increases brake pressure – if necessary – to reach a value appropriate to the situation. In the case of an emergency braking manoeuvre, ABS prevents the wheels from locking up. The additional braking power provided by BAS pro is removed as soon as the brake pedal is released or if there is no longer any danger of collision .