Driving and operating 187The minimum indicated distance is0.5 s.If there is no vehicle ahead or thevehicle ahead is out of range, twodashes will be displayed: -.- s.Active Emergency BrakingActive emergency braking can help toreduce the damage from crashes withvehicles and obstacles directlyahead, when a collision can no longerbe avoided either by manual brakingor by steering. Before the activeemergency braking applies, the driveris warned by the forward collisionalert 3 183.The feature uses various inputs (e.g.radar sensor, brake pressure, vehiclespeed) to calculate the probability ofa frontal collision.Active emergency braking operatesautomatically above walking speed,provided that Auto collisionpreparation setting is not deactivatedin the vehicle personalisation menu3 127.The system includes:■ Brake preparation system■ Emergency automatic braking■ Forward looking brake assist9 WarningThis system is not intended toreplace the driver responsibility ofdriving the vehicle and lookingahead. Its function is limited tosupplemental use only. The drivershall continue to apply the brakepedal as the driving situationdictates.Brake preparation systemWhen approaching a vehicle aheadso quickly that a collision is likely, thebrake preparation system slightlypressurises the brakes. This reducesthe response time, when a manual orautomatic braking is requested.The brake system is prepared so thatbraking can occur more rapidly.Emergency automatic brakingAfter the brake preparation and justbefore the imminent collision, thisfunction automatically applies limitedbraking to reduce the impact speed ofthe collision.Forward looking brake assistIn addition to brake preparationsystem and emergency automaticbraking, the forward looking brakeassist function makes the brake assistmore sensitive. In this way,depressing the brake pedal slightly
