brake MERCEDES-BENZ M-Class 2014 W166 Owner's Guide

systems can neither reduce the risk of
accident nor override the laws of physics.
Driving safety systems are merely aids
designed to assist driving. You are
responsible for the distance to the vehicle in
front, for vehicle speed and for braking in
good time. Always adapty our driving style to
suit the prevailing road and weather
conditions and maintain asafe distance from
the vehicle in front. Drive carefully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tires and
the road surface. Please pay special
attention to the note son tires,
recommended minimu mtire tread depths,
etc. (Y page 398).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible. ABS (Anti-lock Braking System)
General information AB
Sr egulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
The 0019 ABSw arning lamp in the instrument
cluste rlights up when the ignition is switched
on. It goes out when the engine is running.
Important safety notes i
Observe the "Importan tsafety notes"
sectio n(Ypage 66). G
WARNING
If ABSi s faulty, the wheels could lock when
braking. The steerability and braking
characteristics may be severely impaired.
Additionally, further driving safety systems
are deactivated. There is an increased danger
of skidding and accidents. Drive on carefully. Have ABS checked
immediately at a qualified specialist
workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp (Y page 318) and
display messages which may be shown in the
instrument cluster (Y page 283).
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface
conditions. ABS works on slippery surfaces,
even if you only brake gently.
Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking
situation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving.
Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y
page 248).
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The
digging-in effect achieved in the process
reduces the stopping distance on off-road
terrain. This limits steering capability. BAS (Brake AssistS
ystem)
General information BAS operates in emergency braking
situations. If you depress the brake pedal Driving safety systems
67Safety Z

quickly, BASa
utomatically boosts the braking
force, thus shortening the stopping distance.
Important safety notes i
Observe the "Importan tsafety notes"
sectio n(Ypage 66). G
WARNING
If BASi s malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal.B AS is deactivated.BAS PLUS (Brake Assist System
PLUS)
General information i
Observe the "Important safety notes"
sectio n(Ypage 66).
BASP LUS is only available in vehicles
equipped with DISTRONIC PLUS.
For BAS PLUS to assist you, the radars ensor
system must be operational.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
If the radar sensor system is malfunctioning,
BASP LUS will not be available. The brake
system is still available with complete brake
boosting effect and BAS.
BAS PLUS can help you to minimize the risk
of a collision with a vehicle or reduce the
effects of such a collision. If BAS PLUS detects a danger of collision, you are assisted
when braking.
Important safety notes G
WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. Terminate the
intervention in a non-critical driving situation. G
WARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As aresult, BAS PLUS may not intervene in all
critical situations. There is a risk of an
accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In the event of snowfall or heavy rain, the
recognition can be impaired.
Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering the sensors
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in fron tonadifferent line
relative to the center of your vehicle
Following damage to the fron tend of the
vehicle, have the configuratio nand operation
of the rada rsensors checked at a qualified 68
Driving safet
ysystemsSafety

specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
Function To avoid a collision, BAS PLUS calculates the
brake force necessary if:
R you approach an obstacle, and
R BAS PLUS has detected arisk of collision
When driving at a speed under 20 mph
(30 km/h):ify ou depress the brake pedal,
BAS PLUS is activated. The increase in brake
pressure will be carried out at the last
possible moment.
When driving at a speed above 20 mph
(30 km/h) :ifyou depress the brake pedal
sharply, BAS PLUS automatically raises the
brake pressure to a value adapted to the
traffic situation.
BAS PLUS provides braking assistance in
hazardous situations with vehicles in front
within a speed range between 4mph
(7 km/h) and 155 mph (250 km/ h).
At speeds of up to approximately 40 mph
(70 km/h), BAS PLUS can also react to
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
i If BAS PLUS demands particularly high
braking force, preventative passenger
protection measures (PRE-SAFE ®
) are
activated simultaneously.
X Keep the brake pedal depressed until the
emergency braking situatio nis over.
ABS prevents the wheels from locking.
BAS PLUS is deactivated and the brakes
function as usual again, if:
R you release the brake pedal
R there is no longer a risk of collision
R no obstacle is detected in front of your
vehicle
If you have activated DSR (Y page 246), BAS
PLUS is likewise deactivated. COLLISIONP
REVENTIONASSIST
General notes COLLISION PREVENTION ASSIST consists of
Adaptive Brake Assist and the distance
warning function, which are described in the
following.
Distance warning function
Important safety notes
i
Observe the "Important safety notes"
section (Y page 66). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay careful attention to the traffic
situation and do not rely solely on the distance
warning function.
Function
X To activate/deactivate: activate or
deactivate the distance warning function in
the on-board computer (Y page 272). Driving safety systems
69Safety Z

If the distance warning function is not
activated, the
0001symbol appears in the
assistance graphics display.
The distance warning function can help you
to minimize the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision. If the distance warning
function detects that there is a risk of a
collision, you will be warned visually and
acoustically. The distance warning function
cannot prevent a collision withou tyour
intervention.
Starting at a speed of around 4 mph
(7 km/h), the distance warning function
warns you if you rapidly approach a vehicle in
front. An intermittent warning tone will then
sound, and the 000Edistance warning lamp
will light up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action, provided it is safe to
do so.
Due to the nature of the system, particularly
complicated but non-critical driving
conditions may also cause the system to
display a warning.
With the help of the radar sensor system, the
distance warning function can detect
obstacles that are in the path of your vehicle
for an extended period of time.
From a speed of around 40 mph (70 km/h),
the distance warning function can also react
to stationary obstacles, such as stopped or
parked vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision,
the system will initially alert you both visually
and acoustically.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources R
there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
Adaptive Brake Assist i
Observe the "Important safety notes"
section (Y page 66). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic
situations. In these cases, Adaptive Brake
Assist may not intervene. There is a risk of an
accident.
Always pay careful attention to the traffic
situation and be ready to brake. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving
conditions may also cause Brake Assist to
intervene.
Adaptive Brake Assist aids you in braking
during hazardous situations at speeds above 70
Driving safety systemsSafety

20 mph (30 km/h) and uses the radar sensor
system to evaluate the traffic situation.
With the help of Adaptive Brake Assist, the
distance warning signal can detect obstacles
that are in the path of you rvehicle for an
extended period of time.
Should you approach an obstacle and
Adaptive Brake Assist has detected a risk of
collision, Adaptive Brake Assist calculates the
braking force necessary to avoid a rear-end
collision. Should you apply the brakes
vigorously, Adaptive Brake Assist will
automatically increase the braking force to a
level suitable for the traffic conditions.
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal
R there is no longer any danger of a rear-end
collision
R no obstacle is detected in fron tofyour
vehicle
Adaptive Brake Assist is then deactivated.
If Adaptive Brake Assist requires particularly
high brake pressure, preventive passenger
protection measures (PRE-SAFE ®
) are
deployed simultaneously.
Up to vehicle speeds of around 155 mph
(250 km/h), adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
If Adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain R
interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section (Y page 66).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tires and
the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilize the vehicle during braking.
ETS/4ETS (Electronic Traction System) ETS/4ETS traction control is part of ESP
®
.
Traction control brakes the drive wheels
individually if they spin. This enables you to
pull away and accelerate on slippery surfaces,
for example if the road surface is slippery on
one side. In addition, more drive torque is
transferred to the wheel or wheels with
traction.
Traction control remains active, even if you
deactivate ESP ®
.
In appropriate driving situations, activate the
off-road program (Y page 248). Driving safety systems
71Safety Z

Off-road 4ETS (Electronic Traction
System) A4
ETS syste mspecifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 248).
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! Vehicles with 4MATIC: only operate the
vehicle for a maximum of ten seconds on a
brake test dynamometer. Switch off the
ignition.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! Vehicles with 4MATIC: function or
performance tests may only be carried out
on a 2-axle dynamometer. Before you
operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage
the drive train or the brake system.
ESP ®
is deactivated if the 0017warning lamp
in the instrument cluster lights up
continuously when the engin eis running.
If the 000F warning lamp and the 0017
warning lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 321) and displaym essages which
may be shown in the instrument cluster
(Y page 283).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly. Characteristics of ESP
® General information
If the
000F ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the 000FESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any
circumstances.
X Only depress the accelerator pedal as far
as necessary when pulling away.
X Adapt your driving style to suit the
prevailing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving. The engine starts
automatically when the driver wants to pull
away again. ESP ®
remains in its previously
selected status. Example:if ESP®
was
deactivated before the engin ewas switched
off, ESP ®
remains deactivated when the
engine is switched on again.
Deactivating/activating ESP ® Important safety notes
You can selec
tbetween the following states
of ESP ®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer
stabilizes the vehicle. There is an increased
risk of skidding and an accident.
Only deactivate ESP ®
in the situations
described in the following. 72
Driving safet
ysystemsSafety

It may be best to deactivate ESP
®
in the
following situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the
vehicle if the vehicle starts to skid or a
wheel starts to spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
Deactivating/activating ESP ®X
To switch off: press button0002.
The 0017 ESP®
OFF warning lamp in the
instrument cluster lights up.
X To switch on: press button0002.
The 0017 ESP®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the 000FESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin. The spinning of the wheels results in a
cutting action for better traction on loose
surfaces.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
Off-road ESP ® An ESP
®
system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 248).
Off-road ESP ®
intervenes with a delayift here
is oversteering or understeering, thus
improving traction.
ESP ®
trailer stabilization G
WARNING
If road and weather conditions are poor,
trailer stabilization will not be able to prevent
the vehicle/trailer combination from
swerving. Trailers with a high center of gravity
can tip over before ESP ®
can detect this.
There is a risk of an accident.
Always adapt your driving style to the
prevailing road and weather conditions.
If your vehicle with trailer (vehicle/trailer
combination) begins to lurch, you can only
stabilize the vehicle/trailer combination by
depressing the brake firmly.
In this situation, ESP ®
assists you and can
detect if the vehicle/trailer combination
begins to lurch. ESP ®
slows the vehicle down
by braking and limiting the engine output until
the vehicle/trailer combination has
stabilized.
Trailer stabilization is active above speeds of
about 37 mph (60 km/h).
Trailer stabilization does not work if ESP ®
is
deactivated because of a malfunction. Driving safety systems
73Safety Z

EBD (electronic brake force
distribution)
General information EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking.
Important safety notes
i
Observe the "Important safety notes"
sectio nfor driving safety systems
(Y page 66). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This
increases the risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified
specialist workshop.
Observe information regarding indicator and
warning lamps (Y page 319) as well as
display messages (Y page 285).ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 206) and hill start assist
(Y page 161). PRE-SAFE
®
Brake
General information i
Observe the "Important safety notes"
section (Y page 66).
PRE-SAFE ®
Brake is only available in vehicles
with DISTRONIC PLUS.
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
operational. With the help of the radar sensor system,
PRE-SAFE
®
Brake can detect obstacles that
are in front of your vehicle for an extended
period of time.
PRE-SAFE ®
Brake can help you to minimize
the risk of a collision with a vehicle ahead, and
reduce the effects of such a collision. If PRE-
SAFE ®
Brake has detected a risk of collision,
you will be warned visually and acoustically
as well as by automatic braking. PRE-SAFE ®
Brake cannot prevent a collision without your
intervention.
Important safety notes G
WARNING
PRE-SAFE ®
Brake will initially brake your
vehicle by a partial application of the brakes
if a danger of collision is detected. There may
be a collision unless you also brake.
Automatic emergenc ybraking cannot prevent
a collision. There is a risk of an accident.
Always apply the brakes yourself and try to
take evasive action. G
WARNING
PRE-SAFE ®
Brake cannot always clearly
identify objects and complex traffic
conditions.
In these cases, PRE-SAFE ®
Brake may:
R give an unnecessary warning and then
brake 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 be ready to brake, especially if
PRE-SAFE ®
Brake warns you. Terminate the
intervention in a non-critical driving situation.
In order to maintai nthe appropriate distance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself. 74
Driving safety systemsSafety

G
WARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, PRE-SAFE ®
Brake may neither
give warnings nor intervene in all critical
situations. There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
In the event of snowfall or heavy rain, the
recognitio ncan be impaired.
Recognition by the radar sensor system is
also impaired in the event of:
R dirt on the sensors or anything else
covering the sensors
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in fron tonadifferent line
relative to the center of your vehicle
Following damage to the fron tend of the
vehicle, have the configuratio nand operation
of the rada rsensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the fron tofthe vehicle.
Function X
To activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer (Y page 272).
If the PRE-SAFE ®
Brake is not activated, the
0001 symbol appears in the multifunction
display.
Starting at a speed of around 4 mph
(7 km/h), this function warns you if you
rapidly approach a vehicle in front.An
intermitten twarning tone will then sound and the
000E distance warning lamp will light up
in the instrument cluster.
X Brake immediately to defuse the situation.
or
X Take evasive action provide ditis safe to do
so.
PRE-SAFE ®
Brake can also brake the vehicle
automatically under the following conditions:
R the driver and front-passenger have their
seat belts fastened
and
R the vehicle speed is between
approximately 4mph (7 km/h) and
124 mph (200 km/h)
At speeds of up to approximately 40 mph
(70 km/ h)PRE-SAFE ®
Brake can also detect
stationary objects. Examples of stationary
objects are stopped or parked vehicles.
i If there is an increased risk of collision,
preventive passenger protection measures
(PRE-SAFE ®
) are activated.
If the risk of collision with the vehicle in front
remains and you do not brake, take evasive
action or accelerate significantly, the vehicle
may perform automatic emergency braking,
up to the point of full brake application.
Automatic emergency braking is not
performed until immediately prior to an
imminent accident.
You can prevent the intervention of the PRE-
SAFE ®
Brake at any time by:
R depressing the accelerator pedal further.
R activating kickdown.
R releasing the brake pedal.
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you maneuver to avoid the obstacle.
R there is no longer any danger of a rear-end
collision.
R there is no longer an obstacle detected in
front of your vehicle. Driving safety systems
75Safety Z

If you have activated DSR (Y
page 246), PRE-
SAFE ®
Brake is deactivated. STEER CONTROL
General information STEER CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake.
R the vehicle starts to skid.
Important safety notes i
Observe the "Important safety notes"
section (Y page 66).
If ESP ®
is malfunctioning, you will not receive
steering support from STEER CONTROL.
Powers teering will, however, continue to
function. Theft deterrent locking system
Immobilizer
X To activate with the SmartKey: remove
the SmartKey from the ignition lock.
X To activate with KEYLESS-GO: switch the
ignition off and open the driver's door.
X To deactivate: switch on the ignition.
The immobilize rprevents yourv ehicle from
being started without the correct SmartKey.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle.
Anyone can start the engine if a valid
SmartKey has been left inside the vehicle.
i The immobilizer is always deactivated
when you start the engine. In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contac
tanauthorized Mercedes-Benz
Cente rorcall 1-800-FOR-MERCedes (in the
USA) or 1-800-387-0100 (in Canada). ATA (anti-theft alarm system)
X
To arm: lockthe vehicle with the SmartKey
or KEYLESS-GO.
Indicator lamp 0002flashes. The alarm
system is armed after approximately
15 seconds.
X To disarm using the SmartKey: unlock
the vehicle with the SmartKey.
or
X Insert the SmartKey into the ignition lock.
X To disarm using KEYLESS-GO: unlock the
vehicle with KEYLESS-GO.
or
X Press the Start/Stop button on the
dashboard. The SmartKey must be inside
the vehicle.
Av isual and audible alarm is triggered if the
alarm system is armed and you open:
R a door
R the vehicle with the mechanical key
R the tailgate
R the hood 76
Theft deterrent locking systemSafety