
The proactive occupant protection system is an assistance system that initiates measures to protect
vehicle occupants in dangerous situations. However, the system cannot prevent a collision.
The full range of functions of the proactive occupant protection system will be available only if the
function has been activated in the Infotainment system, no special driving profile has been selected
and there are no malfunctions Driving profile selecFunction
limitations
Basic functions
Depending on country-specific legal requirements and also on the vehicle equipment, the following
functions may be initiated, either individually or jointly, in critical situations (e.g. emergency braking
or in the case of oversteering or understeering) as of a speed of approximately 30 km/h (19 mph):
Reversible tensioning of the fastened front seat belts.
Depending on the critical driving situation, the seat belts can be tensioned separately or together.
Additional information for vehicles with an area monitoring system (Front Assist)
In vehicles fitted with the area monitoring system (Front Assist) Area monitoring system (Front
Assist)
limits. The system can trigger the proactive occupant protection system if it detects a probable
collision or initiates strong braking.
Function limitations
The proactive occupant protection system will not be available, or will be available only to a limited
extent, in the following situations:
If there is a fault in the ESC, belt tensioner Seat beltsor airbag control unit Airbag system
WARNING
The intelligent technology of the proactive occupant protection system cannot overcome the laws of
physics, and functions only within the limits of the system. Never let the extra convenience afforded
by the proactive occupant protection system tempt you into taking any risks when driving. The
system cannot prevent a collision. The system is not a substitute for the full concentration of the
driver.
Adapt your speed and distance from the vehicles ahead to suit visibility, weather, road and traffic
conditions.
The system cannot detect objects in all situations.
The proactive occupant protection system does not react to people, animals, objects crossing in
front of the vehicle, or objects which are hard to detect.

corresponding message on the instrument cluster. In addition, the red warning lamp lights up
and an acoustic warning is given. Brake immediately!
Radar sensor
ACC detects driving situations by means of the radar sensor at the front of the vehicle Front view
The radar sensor has a range of up to approximately 120 m.
WARNING
The intelligent technology used in the ACC cannot overcome the laws of physics, and functions only
within the limits of the system. Never let the extra convenience tempt you into taking safety risks
when driving. Careless or unintentional use of the Adaptive Cruise Control (ACC) can cause accidents
and lead to serious injury. The system is not a substitute for the full concentration of the driver.
Adapt your speed and distance from the vehicles ahead to suit visibility, weather, road and traffic
conditions.
Never use the ACC in poor visibility, on steep or winding roads, or on slippery road surfaces e.g. due
to snow, ice, wet roads, loose chippings, or on flooded roads.
Never use the ACC offroad or on non-surfaced roads. The ACC is designed for use on surfaced roads
only.
The ACC will not react to stationary vehicles.
The ACC will not react to persons, animals or vehicles crossing or approaching in the same lane.
Brake immediately if speed reduction by ACC is not sufficient.
Brake immediately if a request to brake appears on the instrument cluster display.
Brake if the vehicle starts rolling unintentionally after a request to brake.
Be prepared to control the speed yourself at all times.
Special driving situations
Fig. 118 On the instrument cluster display: slower vehicle detected in the left-hand lane (illustration).

Radar sensor
Front Assist detects driving situations by means of the radar sensor at the front of the vehicle
Front view m.
Functions included in the system
The City Emergency Braking System and Pedestrian Monitoring (depending on vehicle equipment)
are part of Front Assist and are automatically active when Front Assist is switched on.
WARNING
The intelligent technology used in Front Assist cannot overcome the laws of physics, and functions
only within the limits of the system. Never let the extra convenience afforded by Front Assist tempt
you into taking safety risks when driving. The driver is always responsible for braking in time.
If Front Assist issues a warning, brake your vehicle immediately depending on the traffic situation or
avoid the obstacle.
Adapt your speed and distance from the vehicles ahead to suit visibility, weather, road and traffic
conditions.
Front Assist cannot prevent accidents and serious injuries on its own.
Front Assist can issue unnecessary warnings and carry out unwanted braking interventions in certain
complex driving situations, e.g. at traffic islands.
Front Assist can issue unnecessary warnings and carry out unwanted braking interventions when its
function is impaired, e.g. if the radar sensor is dirty or its position has been changed.
Front Assist without Pedestrian Monitoring does not react to persons. In addition, the system does
not react to animals or to vehicles that are crossing or approaching in the same lane.
If you are unsure whether your vehicle possesses Pedestrian Monitoring, please enquire about this
at a qualified workshop before starting your journey.
Be prepared to take over control of the vehicle yourself at all times.
Warning levels and braking intervention
First read and observe the introductoryinformation and safety warnings
Distance warning
The system detects when safety is endangered by driving too close to the vehicle in front. The
warning lamp lights up. Increase the distance.
Speed range: around 65 km/h (40 mph) to 250 km/h (155 mph).
Advance warning

Vehicles that are driving outside the sensor range in close proximity to your vehicle, e.g. vehicles
that are driving offset to your vehicle or motorbikes.
Vehicles that change into your lane directly in front of your vehicle.
Vehicles with bodies or attachments that project beyond the vehicle.
Oncoming vehicles or vehicles crossing your path.
Pedestrians who are stationary, moving towards the vehicle or moving in the same direction as the
vehicle.
Function limitations
In tight bends.
Driving in heavy rain, snow or heavy spray.
Driving in multi-storey car parks.
Driving on roads with embedded metal objects, e.g. railway tracks.
Reversing.
If TCS is switched off manually.
If ESC is taking corrective action.
If the radar sensor is dirty or covered.
If there is a fault in several brake lights on the vehicle or on a trailer with an electrical connection to
the vehicle
If the vehicle accelerates hard or the accelerator is fully depressed.
In complex driving situations, e.g. at traffic islands.
In unclear traffic situations, e.g. vehicles ahead are braking heavily or turning off.
If there is a fault in Front Assist.
Switching off Front Assist
If the vehicle is used in a capacity other than driving in normal traffic, e.g. offroad.
If the vehicle is being towed or is loaded onto another vehicle.
If the radar sensor is covered temporarily by add-on parts, e.g. auxiliary headlights.
If the radar sensor is faulty.
After external force on the radar sensor, e.g. after a frontal collision.
In the event of multiple unwanted interventions.

Failure to switch off Front Assist in the situations mentioned can result in accidents and serious
injuries.
Pedestrian Monitoring
First read and observe the introductoryinformation and safety warnings
Pedestrian Monitoring can help to avoid accidents with pedestrians crossing the vehicle's path or to
mitigate the consequences of an accident.
The system gives a warning when there is a risk of collision, prepares the vehicle for emergency
braking, helps to brake the vehicle or performs an automatic brake intervention. In the event of an
advance warning, the warning lamp lights up in the instrument cluster
When Front Assist is switched on, Pedestrian Monitoring is active as part of Front Assist in a vehicle
speed range from approx. 5 km/h (3 mph) to 65 km/h (40 mph).
Pedestrian Monitoring is not available in all countries, depending on the vehicle equipment level.
WARNING
The intelligent Pedestrian Monitoring technology cannot overcome the laws of physics, and
functions only within the limits of the system. Never let the extra convenience afforded by the
Pedestrian Monitoring system tempt you into taking any safety risks when driving. The driver is
always responsible for braking in time.
If Pedestrian Monitoring issues a warning, brake your vehicle immediately depending on the traffic
situation or avoid the pedestrian.
Pedestrian Monitoring cannot prevent accidents and serious injuries on its own.
Pedestrian Monitoring can issue unnecessary warnings and carry out unwanted braking
interventions in complex driving situations, e.g. on a main road that turns sharply.
Pedestrian Monitoring can issue unnecessary warnings and carry out unwanted braking
interventions when its function is impaired, e.g. if the radar sensor is covered or its position has
been changed.
Be prepared to take over control of the vehicle yourself at all times.
Operating the area monitoring system (Front Assist)
First read and observe the introductoryinformation and safety warnings
Front Assist and the advance warning (in some countries) are automatically switched on when you
switch on the ignition.
However, the system is not available or its functions are restricted for a period of around 30 seconds
(also longer, depending on the driving situation).