
of the vehicle and prepares the vehicle for a possible emergency braking procedure. 
A warning tone sounds and the red warning lamp lights up. Brake or take avoiding action. 
Speed range: around 30 km/h (20 mph) to 250 km/h (155 mph). 
Urgent warning 
If the driver does not react to the advance warning, the system may initiate a short braking jolt in 
order to draw attention to the increasing collision risk. Brake or take avoiding action. 
Speed range: around 30 km/h (20 mph) to 250 km/h (155 mph). 
Automatic braking 
If the driver also does not react to the urgent warning, the vehicle can be braked automatically with 
braking force that increases in several stages. The reduced speed means that it is possible to 
minimise the consequences of an accident. 
Speed range: around 5 km/h (3 mph) to 250 km/h (155 mph). 
Braking intervention 
If the system detects that the driver is braking insufficiently when there is a risk of collision, the 
system can increase the braking force and help prevent a collision. The braking intervention takes 
place only for as long as the brake pedal is pressed hard. 
Speed range: around 5 km/h (3 mph) to 250 km/h (155 mph). 
City Emergency Braking System 
The City Emergency Braking System is part of Front Assist. If the driver does not react to a possible 
collision, the system can also automatically brake the vehicle with increasing braking force without 
any advance warning. 
The red warning lamp lights up  
Speed range: around 5 km/h (3 mph) to 30 km/h (20 mph). 
Limits of Front Assist 
First read and observe the introductoryinformation and safety warnings
Front Assist is not available or its functions are restricted for a period of around 30 seconds (also 
longer, depending on the driving situation) immediately after the vehicle is started. 
Front Assist has physical and system-related limitations. You should therefore always be prepared to 
take full control of the vehicle if necessary. 
Delayed response 
If the radar sensor is exposed to environmental conditions that impair sensor functioning, the 
system may detect this only after a certain time. For this reason, possible functional restrictions may 
be displayed only after a delay at the start of the journey and when driving   

 
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).  

 
Lane keeping system (Lane Assist) 
 Introduction 
This chapter contains information on the followingsubjects: 
Driving with the lane keeping system
Troubleshooting
The lane keeping system (Lane Assist) helps the driver stay in lane. 
Using a camera in the windscreen, the lane departure warning system detects lane markings on the 
road. If your vehicle moves too close to a recognised lane marking, the system will warn the driver 
with a corrective steering intervention. The corrective steering intervention can be overridden by 
the driver at any time. 
Adaptive lane guidance (depending on vehicle equipment) 
The adaptive lane guidance system detects the preferred position in a lane and keeps the vehicle in 
this position. 
Adaptive lane guidance is switched on and off in the Driver assistance menu in the Infotainment 
system Vehicle settings menu 
System limits 
Use the lane keeping system only on motorways and good main roads. 
The system is not active under the following conditions: 
The lane keeping system has not detected any lane markings. 
 
WARNING 
The intelligent technology used in the lane keeping system cannot overcome the laws of physics, and 
functions only within the limits of the system. Always take care when using the lane departure 
warning system otherwise you could cause accidents or injuries. 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. 
Your hands should always be on the steering wheel so that you can steer at any time. The driver is 
always responsible for staying in lane. 
The lane keeping system cannot recognise all lane markings. Poor road surfaces, road structures or 
objects could be recognised incorrectly as lane markings by the lane keeping system. The lane 
keeping system should be switched off immediately in these situations. 
Follow the information on the instrument cluster display and respond according to the commands.  

 
If the camera's field of view is dirty, covered or damaged, the function of the lane keeping system 
may be impaired. 
 
Some settings can be saved in the user accounts of the personalisation function and can therefore 
change automatically when the user account is changed Personalisation 
Driving with the lane keeping system 
 
Fig. 123 On the instrument cluster display: lane keeping system displays. 
First read and observe the introductoryinformation and safety warnings
Switching the lane keeping system on and off 
Using the button for the driver assist systems, select the corresponding menu option Button for 
driver assist systems 
OR: in the Driver assistance menu in the Infotainment system Vehicle sett
If the indicator lamp  lights up yellow in the instrument cluster display, the lane keeping system 
is switched on but is not active. 
The lane keeping system is active at speeds above approximately 65 km/h (40 mph) when lane 
markings can be identified System limits  lights up green. 
Displays 
Display areas in the instrument cluster display Fig. 123 
Lane markings detected. System not regulating. 
Lane markings detected. System is regulating. 
No lane markings detected. System not regulating. 
Lane markings detected. System is regulating. Adaptive lane guidance active.  

 
Switch off the lane keeping system in the following situations: 
Very sporty driving. 
In poor weather conditions and when driving on poor roads. 
In roadworks and before crests in the road. 
Driver intervention prompt 
In the absence of any steering input, the system prompts the driver with acoustic warnings and a 
display on the instrument cluster display to take over active steering. 
If the driver does not respond, the system will give another warning by initiating a quick jolt of the 
brake before switching to passive mode or activating Emergency Assist (with some equipment 
levels). 
Steering wheel vibration 
The following situations can lead to vibration of the steering wheel: 
If the corrective steering intervention is not sufficient to keep the vehicle in its lane. 
If the system can no longer detect a lane during a significant steering intervention. 
 
If there is a system fault, the lane keeping system can deactivate itself automatically. 
Troubleshooting 
First read and observe the introductoryinformation and safety warnings
No camera visibility, error message, system switches itself off 
Clean the windscreen Caring for and cleaning the vehicle exterior 
Check whether any damage is visible on the windscreen in the camera's field of view. 
The system is not responding as expected 
Regularly clean the camera's field of view, and keep it free from snow and ice. 
Do not cover the camera's field of view. 
Check the area of the windscreen that is in the camera's field of view for damage. 
Do not fit any objects to the steering wheel. 
Traffic Jam Assist 
Traffic Jam Assist helps the driver to keep in lane, and also provides assistance when following other 
vehicles in congestion or slow-moving traffic.  

 
Driving through road works. 
In urban areas. 
 
WARNING 
The intelligent technology of Traffic Jam Assist cannot overcome the laws of physics, and functions 
only within the limits of the system. Always take care when using Traffic Jam Assist as you could 
otherwise cause accidents or injuries. 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. 
Do not use Traffic Jam Assist in urban traffic. 
Do not use Traffic Jam Assist in poor visibility, on steep or winding roads, or on slippery road 
surfaces e.g. on snow, ice, wet roads, loose chippings or flooded roads. 
Never use Traffic Jam Assist offroad or on unsurfaced roads. Traffic Jam Assist is designed solely for 
use on surfaced roads. 
Traffic Jam Assist does not react to persons, animals or vehicles crossing or approaching in the same 
lane. 
If the speed reduction achieved by Traffic Jam Assist is insufficient, brake the vehicle immediately by 
depressing the foot brake. 
If the vehicle starts to roll unintentionally after the driver has been prompted to take control of the 
vehicle, brake the vehicle immediately using the foot brake. 
If a driver intervention prompt appears on the instrument cluster display, take control of the vehicle 
immediately. 
Your hands should always be on the steering wheel so that you can steer at any time. The driver is 
always responsible for staying in lane. 
The driver must be prepared to take control of the vehicle (by accelerating or braking) at all times. 
 
If Traffic Jam Assist does not function as described in this chapter, do not use the system and go to a 
qualified workshop. 
 
If there is a fault in the system, visit a qualified workshop and have the system checked. 
Semi-automatic vehicle control in a medical emergency (Emergency Assist)  

the driver and can keep the vehicle in lane 
automatically, or brake the vehicle to a standstill if required. The system can therefore actively help 
to prevent an accident. 
Emergency Assist is an extension of the lane keeping system (Lane Assist), and combines these 
functions with the Adaptive Cruise Control (ACC). Please therefore read both these chapters and 
observe the information about the system limits and warnings. 
Description 
If there is no driver activity, Emergency Assist prompts the driver to take control of the vehicle again 
by visual and acoustic warnings and by braking jolts. 
If the driver remains inactive, the system automatically controls the accelerator, brake and steering 
to slow the vehicle down and keep it in lane t stopping distance, the system 
decelerates the vehicle to a complete stop and switches on the electronic parking brake 
automatically Operating the electronic parking brake 
When Emergency Assist is actively controlling the vehicle, the hazard warning lights are switched on 
and the vehicle performs slight snaking movements within its lane to warn other road users. 
The hazard warning lights can be deactivated by pressing the accelerator or brake, by making a 
steering intervention or, depending on the situation, by pressing the button for the hazard warning 
lights. 
When Emergency Assist has been triggered, the system is not available again until the ignition has 
been switched off and then back on. 
Prerequisites 
The lane keeping system and ACC are switched on. 
The selector lever is in position D/S or in the Tiptronic gate. 
The system has detected a lane marking on both the right and left sides of the vehicle Fig. 123 
Switching Emergency Assist on and off 
Emergency Assist is activated automatically when the lane keeping system Driving with the lane 
keeping systemis switched on. 
 
WARNING 
The intelligent technology used in Emergency Assist cannot overcome the laws of physics, and 
functions only within the limits of the system. The driver is always responsible for controlling the 
vehicle. 
Adapt your speed and distance from the vehicles ahead to suit visibility, weather, road and traffic 
conditions. 
Your hands should always be on the steering wheel so that you can steer at any time. 
Emergency Assist cannot always prevent accidents and serious injuries on its own.  

the Blind Spot Monitor can cause accidents and serious injuries. 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. 
Your hands should always be on the steering wheel so that you can steer at any time. 
Pay attention to the indicator lamps in the exterior mirrors and in the instrument cluster display and 
respond according to the commands. 
Always pay close attention to the surroundings of the vehicle. 
Never use the Blind Spot Monitor if the radar sensors are dirty, covered or damaged. These 
conditions can impair the proper functioning of the system. 
It may be hard to see the indicator lamp in the exterior mirror in direct sunlight. 
 
Some settings can be saved in the user accounts of the personalisation function and can therefore 
change automatically when the user account is changed Personalisation 
Driving with the Blind Spot Monitor 
 
Fig. 124 In the exterior mirrors: Blind Spot Monitor display. 
First read and observe the introductoryinformation and safety warnings
Switching on and off 
Depending on the vehicle equipment, by means of the button for the driver assist systems Button 
for driver assist systems 
OR: using the Assist systems menu in the instrument cluster. 
OR: with some equipment levels, in the Driver assistance menu in the Infotainment system 
Vehicle settings menu 
When the Blind Spot Monitor is ready for operation, the yellow indicator lamp lights up once 
briefly in the exterior mirrors. 
This most recent system setting is retained even after the ignition has been switched off and on.