permitted. 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.
Monitoring range of the sensors G
WARNING
Active Blind Spot Assist does not detect all
traffic situations and road users. There is a
risk of an accident.
Always make sure that there is sufficient dis-
tance on the side for other traffic or obstacles.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else cover-
ing the sensors
R poor visibility, e.g. due to rain, snow or
spray
Vehicles in the monitoring range are then not indicated.
Active Blind Spot Assist may not detect nar-
row vehicles, such as motorcycles or bicy-
cles, or may only detect them too late. Active Blind Spot Assist monitors the area up
to 10 ft (3 m) behind your vehicle and directly next to your vehicle, as shown in the diagram.
For this purpose, Active Blind Spot Assist
uses radar sensors in the rear bumper. 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:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R the warning is canceled when driving for an
extended period next to long vehicles, such
as trucks.
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 sensors and areas around
them are free of dirt, ice or 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 sensors checked at a qualified specialist workshop.
Blind Spot Assist may otherwise not work
properly.
Indicator and warning display
Active Blind Spot Assist is not active at
speeds below approximately 20 mph
(30 km/h). Vehicles in the monitoring range
are then not indicated. 0043
Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated,
indicator lamp 0043in the exterior mirrors lights 208
Driving systemsDriving and parking
up yellow at speeds of up to 20 mph
(30 km/h). At speeds above 20 mph
(30 km/h), the indicator lamp goes out and
Active Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp 0043on the corre-
sponding side lights up red. This warning is
always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs 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.
Visual and acoustic collision warning
When you switch on the turn signals to
change lanes and a vehicle is detected in the
side monitoring range, you receive a visual
and acoustic collision warning. You then hear a double warning tone and red warning
lamp 0043flashes. If the turn signal remains on,
detected vehicles are indicated by the flash-
ing of red warning lamp 0043. There are no fur-
ther warning tones.
Course-correcting brake application G
WARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the sides.
In very rare cases, the system may make an
inappropriate brake application. An inappro-
priate brake application may be interrupted at any time if you steer slightly in the opposite
direction or accelerate. 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 speed range between 20 mph (30 km/h) and 120 mph (200 km/h).
If a course-correcting brake application
occurs, red warning lamp 0043flashes in the
exterior mirror and the following is shown in
the multifunction display, for example: Either a very slight course-correcting brake
application, or none at all, may occur if:
R there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehi-
cle.
R a vehicle approaches you too closely at the
side.
R you have adopted a sporty driving style with
high cornering speeds.
R you clearly brake or accelerate.
R a driving safety system intervenes, e.g.
ESP ®
or PRE-SAFE ®
Brake.
R ESP ®
is switched off.
R a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X Make sure that Active Blind Spot Assist
(Y page 229) is activated in the on-board
computer.
X Turn the SmartKey to position 2in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow. Driving systems
209Driving and parking Z
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Active Blind Spot Assist is then deactivated. The indicator lamp lights up
yellow in the exterior mirrors and the Active
Active
Blind
Blind Spot SpotAssist
Assist Currently
Currently Unavail‐
Unavail‐
able See Operator's Manual
able See Operator's Manual message
appears in the multifunction display.
Active Lane Keeping Assist General notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of camera 0043
mounted at the top of the windshield. Active
Lane Keeping Assist detects lane markings on
the road and warns you before you leave your
lane unintentionally. If you do not react to the warning, a lane-correcting application of the
brakes can bring the vehicle back into the
original lane. 0043
Active Lane Keeping Assist camera
If you select km kmon the on-board computer in
the Display Unit Speed-/Odometer
Display Unit Speed-/Odometer func-
tion (Y page 230), Active Lane Keeping Assist
is activated starting at a speed of 60 km/h. If
the miles
miles display unit is selected, the assis-
tance range begins at 40 mph.
Important safety notes
If you fail to adapt your driving style, Active
Lane Keeping Assist can neither reduce the
risk of accident nor override the laws of phys-
ics. Lane Keeping Assist cannot take into account the road, traffic and weather condi-
tions. Lane Keeping Assist is merely an aid.
You are responsible for the distance to the
vehicle in front, for vehicle speed, for braking
in good time and for staying in your lane.
Active Lane Keeping Assist cannot continu-
ously keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R not give a warning or intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R there are no, several or unclear lane mark-
ings for a lane, e.g. in areas with road con- struction work
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected 210
Driving systemsDriving an
d parking
G
WARNING
If the ball coupling is not correctly installed
and secured, it could come loose while driving and endanger other road users. There is a risk
of an accident and injury.
Install and secure the ball coupling as descri-
bed in the ball coupling manufacturer's instal- lation instructions. Make sure that the ball
coupling is correctly installed and secured
before every journey. Coupling up a trailer
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law: R safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle.
Leave enough play in the chains to make
tight cornering possible.
R a separate brake system for certain types
of trailer.
R a safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing vehi-
cle, the safety switch applies the trailer's
brakes.
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is equip-
ped with an anti-lock brake system. Doing
so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
i The vehicle's wiring harness features a
connection to the brake indicator lamp. X
Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Close all doors and the tailgate.
X Couple up the trailer.
X Establish all electrical connections. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions:
R in your place of residence
R in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling charac-
teristics, you should practice the following
in a traffic-free location:
- cornering
- stopping
- backing up
R Before driving, check:
- the trailer tow hitch
- the safety switch for braked trailers
- the safety chains
- electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check
whether the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion. Towing a trailer
215Driving and parking Z
R
When you couple up a trailer, check at reg-
ular intervals that the load is firmly secured.If the trailer is equipped with trailer lights
and brakes, check the trailer to ensure that
these are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that the trailer can activate its own brakes. Thenincrease the pressure on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
A lower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
space in relation to the vehicle you are
overtaking, before you can change back to
the original lane. Decoupling a trailer
G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake is engaged.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Close all doors and the tailgate.
X Apply the trailer's parking brake.
X Remove the trailer cable and decouple the
trailer. Permissible trailer loads and drawbar
loads
Weight specifications The gross trailer weight is calculated by add-
ing the weight of the trailer to the weight of
the load and equipment on the trailer.
You will find installing dimensions and loads
under "Technical data" (Y
page 381).
Loading a trailer R
When loading the trailer, make sure that
neither the permissible gross weight of the
trailer nor the gross vehicle weight is
exceeded. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
You can find the maximum permissible val-
ues on the type plates of your vehicle and
the trailer. When calculating how much
weight the vehicle and trailer may carry, 216
Towing a trailerDriving and parking
X
Press 0076to confirm.
X Press the 0064or0063 button to select the
Acoustic Lock
Acoustic Lock function.
If the Acoustic
Acoustic Lock
Lockfunction is activated,
the 0037 symbol in the multifunction dis-
play lights up orange.
X Press the 0076button to save the setting.
Activating/deactivating the radar sensor
system
X Press the 0059or0065 button on the steer-
ing wheel to select the Sett.
Sett. menu.
X Press the 0064or0063 button to select the
Vehicle
Vehicle submenu.
X Press 0076to confirm.
X Press the 0063or0064 button to select
Radar Sensor (See Oper. Manual):
Radar Sensor (See Oper. Manual):.
You will see the selected setting: Enabled Enabled
or Disabled
Disabled.
X Press the 0076button to save the setting.
The following systems are switched off when
the radar sensor system is deactivated:
R DISTRONIC PLUS (Y page 176)
R BAS PLUS (Y page 69)
R PRE-SAFE ®
Brake (Y page 73)
R Blind Spot Assist (Y page 203)
R Active Blind Spot Assist (Y page 207)
Convenience Activating/deactivating the EASY-
ENTRY/EXIT feature
G
WARNING
When the EASY-ENTRY/EXIT feature adjusts
the steering wheel, you and other vehicle
occupants – particularly children – could
become trapped. There is a risk of injury.
While the EASY-ENTRY/EXIT feature is mak-
ing adjustments, make sure that no one has
any body parts in the sweep of the steering
wheel. If somebody becomes trapped:
R press one of the memory function position
buttons, or
R move the switch for steering wheel adjust-
ment in the opposite direction to that in
which the steering wheel is moving.
The adjustment process is stopped.
X Press the 0059or0065 button on the steer-
ing wheel to select the Sett. Sett.menu.
X Press the 0064or0063 button to select the
Convenience
Convenience submenu.
X Press 0076to confirm.
X Press the 0064or0063 button to select the
Easy Entry/Exit
Easy Entry/Exit function.
If the Easy Entry/Exit
Easy Entry/Exit function is activa-
ted, the vehicle steering wheel is displayed in orange in the multifunction display.
X Press the 0076button to save the setting.
Further information on the EASY-ENTRY/EXIT
feature (Y page 108).
Switching the belt adjustment on/off X Press the 0059or0065 button on the steer-
ing wheel to select the Sett.
Sett. menu.
X Press the 0064or0063 button to select the
Convenience
Convenience submenu.
X Press 0076to confirm.
X Press the 0064or0063 button to select the
Belt Adjustment
Belt Adjustment function.
When the Belt Adjustment
Belt Adjustment function is
activated, the vehicle seat belt is displayed in orange in the multifunction display.
X Press the 0076button to save the setting.
For further information on belt adjustment,
see (Y page 59).
Switching the fold-in mirrors when lock-
ing feature on/off
This function is only available on vehicles with
the memory function (Y page 112).
This function is only available in Canada.
When you activate the Auto. Auto.Mirror
Mirror Fold‐
Fold‐
ing
ing function, the exterior mirrors are folded
in when the vehicle is locked. If you unlock the Menus and submenus
233On-board computer and displays Z
Display messages
Possible causes/consequences and
0050
0050Solutions 0027(USA
only)004D
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level Level There is not enough brake fluid in the brake fluid reservoir.
In addition, the
0027(USA only)/ 004D(Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 168).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 0026
Check Brake Pad Check Brake Pad
Wear Wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. 0053
Inoperative
Inoperative One or more main features of the mbrace system are malfunc-
tioning.
X Have the mbrace system checked immediately at a qualified
specialist workshop. PRE-SAFE PRE-SAFE
Inoperative See Inoperative See
Operator's Manual Operator's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. 238
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
0050
0050Solutions PRE-SAFE
PRE-SAFE
Functions Cur‐ Functions Cur‐
rently rently
Limited
Limited See
See
Operator's Manual
Operator's Manual PRE-SAFE
®
Brake is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and the bumper are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
When the causes stated above no longer apply, the display mes-
sage disappears.
PRE ‑SAFE ®
Brake is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 168).
X Clean the sensors in the radiator grill and the bumper
(Y page 309).
X Restart the engine. PRE-SAFE PRE-SAFE
Functions Limited Functions Limited
See See
Operator's
Operator's Man‐
Man‐
ual
ual PRE-SAFE
®
Brake is inoperative due to a malfunction. BAS PLUS or
the distance warning signal may also have failed.
X Visit a qualified specialist workshop. 0075
SRS Malfunction SRS Malfunction
Service required Service required There is a malfunction in the SRS (Supplemental Restraint Sys-
tem). The
0075warning lamp also lights up in the instrument clus-
ter.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about SRS, see (Y page 43). Display
messages
239On-board computer and displays Z