Active Blind Spot Assist
Important safety notes
Active Blind Spot Assist uses a radar sensor system to monitor the side areas of your vehicle which are in back of the driver. A warning display in the exterior mirrors draws your attention to vehicles detected in the monitored area. If you then switch on the corresponding turn signal to change lane, you will also receive an optical and audible collision warning. If a risk of lateral collision is detected, corrective braking may help you avoid a collision. To support the coursecorrecting brake application, Active Blind Spot Assist also uses the forward-facing radar sensor system. Active Blind Spot Assist supports you from speeds of approximately 20 mph (30 km/h).
WARNING
Active Blind Spot Assist is only an aid, and 
may detect vehicles/obstacles incorrectly or 
not at all.
The system may be impaired or may not function if:
• there is poor visibility, e.g. due to snow, rain, fog or spray.
• the rear and/or front sensors are dirty.
Active Blind Spot Assist may not detect 
narrow vehicles, such as motorcycles or 
bicycles, or may only detect them too late. It 
cannot detect vehicles that are overtaken at 
a small distance and then enter the blind spot 
area.
Active Blind Spot Assist cannot detect road 
and traffic conditions. It is not a substitute for 
attentive driving. You are responsible for the 
vehicle's speed, braking in good time, and 
steering correctly. Always adapt your driving 
style to suit the prevailing road and weather 
conditions. Always pay attention to traffic 
conditions and your surroundings. Otherwise, 
you may fail to recognize dangers in time, 
cause an accident and injure yourself and 
others.
 USA only:
 USA only:
This device has been approved by the FCC 
as a “Vehicular Radar System”. The radar 
sensor is intended for use in an automotive 
radar system only. Removal, tampering, or 
altering of the device will void any 
warranties, and is not permitted by the 
FCC. Do not tamper with, alter, or use in 
any non-approved way.
Any unauthorized modification to this 
device could void the user’s authority to 
operate the equipment.
For Active Blind Spot Assist to assist you when driving, the radar sensor system must be activated and operational.
Monitoring area
Active Blind Spot Assist monitors the area shown in the figure up to 10 ft (3 m) behind and immediately adjacent to your vehicle. For this purpose, Active Blind Spot Assist uses radar sensors in the rear bumper.

WARNING
Active Blind Spot Assist monitors certain 
areas in the immediate vicinity of your vehicle.
Vehicles that approach and drive past at high 
speeds are not detected. No visual nor 
audible warnings are emitted and the system 
does not brake the vehicle to correct your 
course.
If the lanes are very wide, it may not be 
possible to monitor the complete width of the 
neighboring lane. For this reason, vehicles in 
the next lane may not be detected, especially 
if they are driving in a staggered formation.
This may be the case if vehicles are driving at 
that edge of their lane which is furthest away 
from your vehicle.
Always pay attention to traffic conditions and 
your surroundings. Otherwise, you may fail to 
recognize dangers in time, cause an accident 
and injure yourself and others.
If the lanes are narrow, vehicles driving in the lane beyond the lane next to your vehicle may be indicated, especially if the vehicles are not driving in the middle of their lane. This may be the case if there are vehicles driving at the inner edge of their lanes.
Due to the nature of the system:
Rwarnings may be issued in error when 
driving close to crash barriers or similar 
solid lane borders.
Rwarnings may be interrupted when driving 
alongside long vehicles, such as trucks, for 
a prolonged time.
Two Active Blind Spot Assist radar sensors are integrated into the front and rear bumpers respectively. An additional radar sensor is located behind the cover in the radiator grill.
Make sure that the sensor areas on the bumpers and the sensor cover in the radiator grill are free of dirt, ice and slush. The rear sensors must not be covered, for example by cycle racks or overhanging cargo. Following a severe impact or in the event of damage to the bumpers, have the function of the radar sensors checked at a qualified specialist workshop. Blind Spot Assist may otherwise not work properly.
Indicator and warning display

Indicator and warning display
1 Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated, indicator lamp 1 lights up yellow in the exterior mirrors up to a vehicle speed of 20 mph (30 km/h). When the vehicle speed exceeds 20 mph (30 km/h), the indicator lamp goes out and Active Blind Spot Assist is ready for use.
When your speed exceeds approximately 20 mph (30 km/h), warning lamp 1 lights up red on the corresponding side whenever a vehicle is detected in the blind spot monitoring range. This warning is always given when a vehicle enters the blind spot monitoring range from behind or from the side. When you are passing another vehicle, the warning is emitted only if the difference in speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse gear is engaged. In this event, Active Blind Spot Assist is no longer active.
The brightness of the indicator/warning lamps is adjusted automatically according to the ambient light.
WARNING
Active Blind Spot Assist is not active at speeds 
lower than 20 mph (30 km/h). The indicator 
lamps in the exterior mirrors are yellow.
Vehicles in the monitoring range are then not 
indicated.
Always pay attention to traffic conditions and 
your surroundings. Otherwise, you may fail to 
recognize dangers in time, cause an accident 
and injure yourself and others.
Visual and audible collision warnings
If you switch on the appropriate turn signals and a vehicle is detected in the side monitoring range, you will receive a visual and acoustic collision warning. You will hear a double warning tone and red warning lamp 1 flashes. If the turn signal remains on, vehicles detected are indicated by the flashing of red warning lamp 1. There are no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lateral collision in the monitoring range, a course-correcting brake application is carried out. This is meant to assist you in avoiding a collision.
The course-correcting brake application is available in the range between 20 mph (30 km/h) and 120 mph (200 km/h).
If a course-correcting brake application occurs, red warning lamp 1 flashes in the exterior mirror and the following is shown in the multifunction display, for example:

WARNING
Active Blind Spot Assist is only an aid 
designed to assist driving. It is not a substitute 
for attentive driving. In some cases, the 
course-correcting brake application is not 
sufficient to avoid a collision. In such a case, 
you must steer, brake or accelerate.
In very rare cases, the system may 
erroneously detect a danger of collision in the 
area of crash barriers or similar lane borders 
and apply the brakes. Active Blind Spot Assist 
does not detect all traffic situations and road 
users. Always make sure that there is 
sufficient distance on the side for other traffic 
or obstacles. An inappropriate brake 
application may be interrupted at any time if 
you steer slightly in the opposite direction or 
accelerate.
You are responsible for driving at appropriate 
speeds, braking in good time, and steering 
correctly. Always adapt your driving style to 
suit the prevailing road and weather 
conditions. Always pay attention to traffic 
conditions and your surroundings. Otherwise, 
you may fail to recognize dangers in time, 
cause an accident and injure yourself and 
others.
There will be either no or only a weak coursecorrecting brake application 
if:
• there are vehicles or obstacles, e.g. crash barriers, located on both sides 
of your vehicle.
• a vehicle approaches you too closely at the side.
• you have adopted a sporty driving style with high cornering speeds.
• you clearly brake or accelerate.
• a driving safety system intervenes, e.g. ESP® or PRE-SAFE® Brake.
• ESP® is switched off.
• a loss of tire pressure or a defective tire is detected.
Switching on Active Blind Spot Assist
 Make sure that the radar sensor 
system 
and Active Blind Spot Assist 
are activated in the on-board 
computer.
 Make sure that the radar sensor 
system 
and Active Blind Spot Assist 
are activated in the on-board 
computer.
 Turn the SmartKey to position 2 
in the 
ignition lock.
 Turn the SmartKey to position 2 
in the 
ignition lock.
Warning lamps 1 light up red in the 
exterior mirrors for approximately 1.5 
seconds and then turn yellow.
See also:
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