Distance warning function
Autonomous braking function
Situation-dependent brake force boosting
Active Brake Assist can help you to minimise the risk of a collision with vehicles or pedestrians or to reduce the effects of such a collision.
If Active Brake Assist has detected a risk of collision, a warning tone sounds and the warning lamp lights up in the instrument cluster.
If you do not react to the warning, autonomous braking can be initiated in critical situations.
In especially critical situations, Active Brake Assist can initiate autonomous braking directly. In this case, the warning lamp and warning tone occur simultaneously with the braking application.
If you apply the brake yourself in a situation detected as critical by Active Brake Assist, or apply the brake during autonomous braking, situation-dependent brake force boosting occurs. The brake pressure increases up to maximum full-stop braking if necessary.
If the autonomous braking function or the situation-dependent brake force boosting is triggered, additional preventive measures for occupant protection (PRE-SAFE®) may also be initiated, if the vehicle is equipped with these.
Active Brake Assist cannot always clearly identify objects and complex traffic situations.
If the system is unavailable, the display appears in the multifunction display.
Observe the system limitations of Active Brake Assist.
Distance warning function
From approximately 30 km/h, if over several seconds the distance maintained to the vehicle travelling in front is insufficient for the driven speed. The
distance warning lamp then lights up in the instrument cluster.
From approximately 7 km/h, if your vehicle is critically close to a vehicle or pedestrian. An intermittent warning tone sounds and the
distance warning lamp lights up in the instrument cluster.
Brake immediately or take evasive action, if it is safe to do so and the traffic situation allows this.
Vehicles travelling in front | Up to approx. 250 km/h |
Stationary vehicles | Up to approx. 80 km/h |
Crossing vehicles | No reaction |
Moving pedestrians | Up to approx. 80 km/h |
Stationary pedestrians | No reaction |
Vehicles travelling in front | Up to approx. 200 km/h |
Stationary vehicles | Up to approx. 50 km/h |
Crossing vehicles | No reaction |
Moving pedestrians | Up to approx. 60 km/h |
Stationary pedestrians | No reaction |
Vehicles travelling in front | Up to approx. 250 km/h |
Stationary vehicles | Up to approx. 80 km/h |
Crossing vehicles | No reaction |
Moving pedestrians | Up to approx. 60 km/h |
Stationary pedestrians | No reaction |
Fully depressing the accelerator pedal or with kickdown.
Releasing the brake pedal.
You manoeuvre to avoid the obstacle.
There is no longer a risk of collision.
An obstacle is no longer detected in front of your vehicle.
Full system performance is not available for a few seconds after switching on the ignition or after driving off.
In snow, rain, fog, heavy spray, if there is glare, in direct sunlight or in greatly varying light conditions.
If the sensors are dirty, misted up, damaged or covered.
If the sensors are impaired due to interference from other radar sources, e.g. strong radar reflections in multi-storey car parks.
If a loss of tyre pressure or a defective tyre has been detected and displayed.
In complex traffic situations where objects cannot always be clearly identified.
For pedestrians or vehicles if they move quickly into the sensor detection range.
For pedestrians who are hidden by other objects.
If the typical outline of a pedestrian cannot be distinguished from the background.
If a pedestrian is not detected as such, e.g. due to special clothing or other objects.
On bends with a tight radius.
The Active Brake Assist sensors adjust automatically while a certain distance is being driven after the vehicle has been delivered. Active Brake Assist is unavailable or only partially available during the teach-in process.
You can watch an animation on this topic at the following link: