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Driving safety systems
Introduction
This section contains information about the
following driving safety systems:
R ABS (
Antilock Brake System)
R Adaptive Brake
R Adaptive Brake Lights
R BAS (
Brake Assist System)
R BAS PLUS (
Brake Assist System PLUS)
R EBP (
Electronic Brake Proportioning)
R ESC (
Electronic Stability Control)
R PRE-SAFE ®
Brake (
Preventive Occupant
Safety System Brake)
i In winter operation, the maximum
effectiveness of most of the driving
systems described in this section is only
achieved with winter tires, or snow chains
as required.
Safety notes
GWarning!
The following factors increase the risk of
accidents:
R Excessive speed, especially in turns
R Wet and slippery road surfaces
R Following another vehicle too closely
The driving safety systems described in this
section cannot reduce these risks or prevent
the natural laws of physics from acting on the
vehicle. They cannot increase braking or
steering efficiency beyond that afforded by
the condition of the vehicle brakes and tires
or the traction afforded.
Only a safe, attentive, and skillful driver can
prevent accidents.
The capabilities of a vehicle equipped with the
driving safety systems described in this
section must never be exploited in a reckless
or dangerous manner which could jeopardize
the user’s safety or the safety of others.
Always adjust your driving style to the
prevailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
If a driving system malfunctions, other driving
safety systems may also switch off. Observe
indicator and warning lamps that may come
on as well as messages in the multifunction
display that may appear.GWarning!
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.
ABS
GObserve Safety notes, see page 63.GWarning!
Do not pump the brake pedal. Use firm, steady
brake pedal pressure instead. Pumping the
brake pedal defeats the purpose of the ABS
and significantly reduces braking
effectiveness.
The Antilock Brake System (ABS) regulates
the brake pressure so that the wheels do not
lock during braking. This allows you to
maintain the ability to steer your vehicle.
The ABS is functional above a speed of
approximately 5 mph (8 km/h) independent
of road surface conditions.
On slippery road surfaces, the ABS will
respond even to light brake pressure.
The ABS indicator lamp ! in the
instrument cluster comes on when you switch
on the ignition. It goes out when the engine
is running.
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Braking
At the instant one of the wheels is about to
lock up, a slight pulsation can be felt in the
brake pedal. The pulsation indicates that the
ABS is in the regulating mode.
XKeep firm and steady pressure on the brake
pedal while you feel the pulsation.
Continuous, steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to steer
the vehicle.
The pulsating brake pedal can be an
indication of hazardous road conditions and
functions as a reminder to take extra care
while driving.
Emergency brake maneuver
XKeep continuous full pressure on the brake
pedal.GWarning!
If the ABS malfunctions, other driving safety
systems such as the BAS or the ESC are also
switched off. Observe indicator and warning
lamps that may come on as well as messages
in the multifunction display that may appear.
If the ABS malfunctions, the wheels may lock
during hard braking, reducing steering
capability and extending the braking distance.
BAS
GObserve Safety notes, see page 63.
The Brake Assist System (BAS) operates in
emergency situations. If you apply the brakes
very quickly, the BAS provides full brake
boost automatically, thereby potentially
reducing the braking distance.
XApply continuous full braking pressure until
the emergency braking situation is over.
The ABS will prevent the wheels from
locking.When you release the brake pedal, the brakes
function again as normal. The BAS is then
deactivated.GWarning!
If the BAS malfunctions, the brake system still
functions, but without the additional brake
boost available that the BAS would normally
provide in an emergency braking maneuver.
Therefore, the braking distance may increase.
BAS PLUS
The Brake Assist System PLUS (BAS PLUS)
operates in emergency braking situations and
uses radar sensors to assess the traffic
situation. BAS PLUS assists you in braking at
speeds above approximately 20 mph
(30 km/h).
When traveling in Canada in a vehicle not
registered in Canada, you must switch off the
radar sensor system ( Y page 236). Canadian
law does not permit the use of the radar
sensor system for vehicles from outside of
Canada.
When you switch off the radar system, the
following functions are deactivated:
R BAS PLUS
R PRE-SAFE ®
Brake ( Y page 69)
R DISTRONIC PLUS ( Y page 330)
R Blind Spot Assist ( Y page 359)
GWarning!
BAS PLUS is a convenience system designed
to assist the driver during vehicle operation.
The responsibility for the vehicle speed and
the distance to the vehicle ahead, including
most importantly brake operation to assure
safe stopping distance, always remains with
the driver.
Always pay attention to traffic conditions
even while BAS PLUS is switched on.
Otherwise, you may not be able to recognize
dangerous situations until it is too late and
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could cause an accident. Personal or fatal
injury to you or others may be the result.
i 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.
BAS PLUS detects obstacles that are in your
driving path for a sufficient period of time to
permit the system to recognize these
obstacles. If you approach the detected
obstacle quickly, BAS PLUS calculates the
level of brake power boost appropriate for the
circumstance to supply when the driver
applies the brakes.
When you step quickly on the brake pedal in
an emergency braking situation, BAS PLUS
automatically regulates the brake power
boost to a level that is suitable for the traffic
situation.
If BAS PLUS requires a particularly high brake
power boost, PRE-SAFE ®
is activated at the
same time.XKeep constant pressure on the brake pedal
until the emergency braking situation is
over.
During this process, the ABS prevents the
wheels from locking up.
The brakes will resume normal operation
after
R the brake pedal is released
R no obstacles are detected in your path
R the system no longer senses a risk of a
collision
BAS PLUS is then deactivated.
BAS PLUS can react to stationary obstacles
such as standing or parked vehicles at road
speeds of up to approximately 40 mph
(70 km/h).
BAS PLUS can only assist you when the radar
sensors are switched on and functional. You
can check whether the sensors are active by
switching on DISTRONIC PLUS
( Y page 330) or using the Radar sensors
function ( Y page 236) in the instrument
cluster control system.GWarning!
BAS PLUS will only respond with brake
assistance if it has clearly detected an object.
Detection can be impeded by
R dirty or covered sensors
R snowfall or heavy rain
R disturbance from other radar sources
R strong radar reflection such as in parking
garages
BAS PLUS uses radar signals that are not
reflected well by narrow objects and
absorptive materials. For this reason BAS
PLUS will not react to persons, animals, and
approaching traffic or cross-traffic.
BAS PLUS may not detect narrow vehicles
driving in front of you, such as motorcycles
and vehicles driving offset from your vehicle
center.
After a hard collision or damage to the front
of the vehicle from an accident, have the
adjustment and operation of the radar
sensors checked by an authorized Mercedes-
Benz Center.
If BAS PLUS is not available due to a radar
sensor malfunction, the braking system will
continue to function normally with full brake
boost and full standard BAS function.
Adaptive Brake
Adaptive Brake provides a high level of
braking safety as well as increased braking
comfort. Adaptive Brake takes driver and
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vehicle characteristics into consideration,
thus achieving an optimal braking effect.
In addiditon, Adaptive Brake provides the
HOLD function (Y page 342) and the hill-start
assist system ( Y page 341).
For more information on the brake system,
see ( Y page 435).
Adaptive Brake Lights
i This function is only available for the
S 600 and the S 65 AMG (USA only).
The brake lamps flash in quick intervals
R while you are braking hard at a speed of
more than 30 mph (50 km/h)
R when you are braking with the aid of BAS
R when you are braking with the aid of BAS
PLUS.
This helps to alert drivers behind you.
If you bring the car to a complete stop by hard
braking at a speed of more than 40 mph
(70 km/h), the hazard warning flasher comes
on automatically as soon as the vehicle is at
a standstill. While the vehicle is stationary,
the brake lamps are continuously lit up. Once
you drive faster than 6 mph (10 km/h)
afterward, the hazard warning flasher goes
out.
EBP
GObserve Safety notes, see page 63.
The Electronic Brake Proportioning (EBP)
enhances braking effectiveness by allowing
the rear brakes to supply a greater proportion
of the braking effort in straight-line braking
without a loss of vehicle stability.
GWarning!
If the EBP malfunctions, the brake system will
still function with full brake boost. However,
the rear wheels could lock up during
emergency braking situations, for example.
You could lose control of the vehicle and
cause an accident.
Adapt your driving style to the changed
driving characteristics.
ESC
GObserve Safety notes, see page 63.
The Electronic Stability Control (ESC) is
operational as soon as the engine is running.
It monitors the vehicle’s traction (force of
adhesive friction between the tires and the
road surface) and handling.
The ESC recognizes that the vehicle deviates
from the direction of travel as intended by the
driver. By applying brakes to individual
wheels and by limiting the engine output, the
ESC works to stabilize the vehicle. The ESC is
especially useful while driving off and on wet
or slippery road surfaces. The ESC also
stabilizes the vehicle during braking and
steering maneuvers.
The ESC warning lamp ÷ in the instrument
cluster comes on when you switch on the
ignition. It goes out when the engine is
running.
GWarning!
Never switch off the ESC when you see the
ESC warning lamp ÷ flashing in the
instrument cluster. In this case proceed as
follows:
R When driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid. The ESC cannot
prevent accidents resulting from excessive
speed.
! Vehicles with 4MATIC:
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Because the ESC operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position 0 or
1 or KEYLESS-GO start/stop button in
position 0 or 1) when the electronic parking
brake is being tested on a brake test
dynamometer.
Active braking action through the ESC may
otherwise seriously damage the brake
system which is not covered by the
Mercedes-Benz Limited Warranty.
! Vehicles without 4MATIC:
Because the ESC operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position 0 or
1 or KEYLESS-GO start/stop button in
position 0 or 1) when the electronic parking
brake is being tested on a brake test
dynamometer or when the vehicle is being
towed with one axle raised.
Active braking action through the ESC may
otherwise seriously damage the brake
system which is not covered by the
Mercedes-Benz Limited Warranty.
! The ESC will only function properly if you
use wheels of the recommended tire size
as specified in the “Technical data” section
of this Operator’s Manual.
i The DISTRONIC PLUS and cruise control
switch off automatically when the ESC
engages.
Electronic Traction System
(ETS/4-ETS) GObserve Safety notes, see page 63.
The ETS (Electronic Traction System) and
4-ETS (four-wheel Electronic Traction
System, vehicles with 4MATIC only) are
components of the ESC. The ETS/4-ETS
improves the vehicle’s ability to utilize
available traction, especially under slippery
road conditions by applying the brakes to a
spinning wheel. Vehicles with 4MATIC also
transfer more power to the wheel(s) with
traction.
When you switch off the ESC, the
ETS/4-ETS is still enabled.
Switching off the ESC
Switching off the ESC (except S 63 AMG)
GWarning!
The ESC should not be switched off during
normal driving other than in the
circumstances described below. Disabling
the system will reduce vehicle stability in
driving maneuvers.
Do not switch off the ESC when a spare wheel
is mounted.
To improve the vehicle’s traction, switch off
the ESC. This allows the drive wheels to spin
and thus cut into surfaces for better grip, for
example
R when driving with snow chains
R in deep snow
R in sand or gravel
GWarning!
Switch on the ESC immediately if the
aforementioned circumstances do not apply
anymore. Otherwise the ESC will not stabilize
the vehicle when it is starting to skid or a
wheel is spinning.
When you switch off the ESC,
R the ESC does not stabilize the vehicle
R the engine output is not limited, which
allows the drive wheels to spin and thus cut
into surfaces for better grip
R the ETS/4-ETS will still apply the brakes to
a spinning wheel
R the ESC continues to operate when you are
braking
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Rthe cruise control or the DISTRONIC PLUS
cannot be activated
R the cruise control or the DISTRONIC PLUS
switch off if activated
i When the ESC is switched off and one or
more drive wheels are spinning, the ESC
warning lamp ÷ in the instrument
cluster flashes. However, the ESC will then
not stabilize the vehicle.XWith the engine running, switch off the ESC
via the control system ( Y page 231).GWarning!
When the ESC OFF warning lamp å is on,
the ESC is switched off.
When the ESC warning lamp ÷ and the
ESC OFF warning lamp å are on
continuously, the ESC is not operational due
to a malfunction.
When the ESC is switched off or not
operational, vehicle stability in standard
driving maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESC.
! Avoid spinning of a drive wheel for an
extended period with the ESC switched off.
This may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Switching off the ESC (S 63 AMG only)
GWarning!
The ESC should not be switched off during
normal driving.
Disabling of the system will result in the
following:
R no restriction to engine torque
R loss of system-supported traction control
“ESC OFF” is designed for driving on closed
tracks when the vehicle’s natural oversteer
and understeer characteristics are desired
and requires a highly skilled and experienced
driver able to handle these critical driving
situations.
You could lose control of your vehicle and
cause an accident.
Please be aware of these limits when you
switch off the ESC.
Do not switch off the ESC when a spare wheel
is mounted.
When you switch off the ESC,
R the ESC does not stabilize the vehicle
R the engine output is not limited, which
allows the drive wheels to spin
R the ETS will still apply the brakes to a
spinning wheel
R the ESC operates while you are braking
R the cruise control or the DISTRONIC PLUS
cannot be activated
R the cruise control or the DISTRONIC PLUS
switch off if activated
i When the ESC is switched off and one or
more drive wheels are spinning, the ESC
warning lamp ÷ in the instrument
cluster flashes. However, the ESC will then
not stabilize the vehicle.XWith the engine running, switch off the ESC
via the control system ( Y page 231).GWarning!
When the ESC OFF warning lamp å is on,
the ESC is switched off.
When the ESC warning lamp ÷ and the
ESC OFF warning lamp å are on
continuously, the ESC is not operational due
to a malfunction.
When the ESC is switched off or not
operational, vehicle stability in standard
driving maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESC.
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! Avoid spinning of a drive wheel for an
extended period with the ESC switched off.
This may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Switching on the ESCXSwitch on the ESC via the control system
( Y page 231).
PRE-SAFE ®
Brake
The PRE-SAFE ®
Brake is available in vehicles
equipped with DISTRONIC PLUS. The PRE-
SAFE ®
Brake can assist you in minimizing the
risk of a rear-end collision with a vehicle in
front of you. The PRE-SAFE ®
Brake may also
reduce the severity of an accident. At speeds
above approximately 20 mph (30 km/h) it will
issue a warning when your vehicle is
approaching the preceding vehicle very
quickly. An intermittent acoustic warning
sounds and the distance warning lamp ·
in the instrument cluster comes on.
When the driver and front passenger have
fastened their seat belts, the PRE-SAFE ®
Brake can also
R brake the vehicle within a speed range of
up to 112 mph (180 km/h) automatically
R activate preventative occupant safety
measures (PRE-SAFE ®
) ( Y page 54)
GWarning!
An intermittent warning sounds and the
distance warning lamp · in the instrument
cluster is illuminated if the PRE-SAFE ®
Brake
calculates that the distance to the vehicle
ahead and your vehicle’s current speed
indicate that the PRE-SAFE ®
Brake will not be
capable of slowing the vehicle sufficiently to
maintain the preset following distance, which
creates a danger of a collision.
Immediately brake your vehicle to increase
the distance between your vehicle and the
vehicle driving in front of you. The warning
sound is intended as a final caution that you
have not interceded with your own braking
inputs to avoid a potentially dangerous
situation. Do not wait for the operation of the
warning signal to intercede with your own
braking, as that will result in potentially
dangerous emergency braking which will not
always result in an impact being avoided.
Tailgating increases the risk of an accident.GWarning!
The PRE-SAFE ®
Brake is a convenience
system designed to assist the driver during
vehicle operation. The responsibility for the
vehicle speed and the distance to the vehicle
ahead, including most importantly brake
operation to assure safe stopping distance,
always remains with the driver.
Always pay attention to traffic conditions
even while the PRE-SAFE ®
Brake is switched
on. Otherwise, you may not be able to
recognize dangerous situations until it is too
late and could cause an accident resulting in
personal or fatal injury to you or others.
i 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.
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iCanada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference received, including
interference that may cause undesired
operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
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.
Using the radar sensors, the PRE-SAFE ®
Brake detects obstacles that are in your
driving path for a sufficient period of time for
the system to recognize it. If you approach a
vehicle and the PRE-SAFE ®
Brake has
established that the distance to the vehicle
ahead at your current speed is so close that
the PRE-SAFE ®
Brake will not be capable of
slowing the vehicle sufficiently, the system
will initially warn you visually and acoustically.
If you do not apply the brakes yourself or
maneuver around a sensed obstacle, the
vehicle will brake lightly automatically. The
PRE-SAFE ®
system ( Y page 54) is activated
when the distance to the vehicle ahead at
your current speed is so close that the PRE-
SAFE ®
Brake will not be capable of slowing
the vehicle sufficiently.
When the danger of a collision still persists
and you do not brake or accelerate
significantly, the PRE-SAFE ®
Brake may
initiate full application of the brakes
automatically.GWarning!
The PRE-SAFE ®
Brake will only respond with
brake assistance if it has clearly detected an
object. Detection can be impeded by
R dirty or covered sensors
R snowfall or heavy rain
R disturbance from other radar sources
R strong radar reflection such as in parking
garages
The PRE-SAFE ®
Brake uses radar signals that
are not reflected well by narrow objects and
absorptive materials. For this reason the PRE-
SAFE ®
Brake will not react to persons,
animals, and approaching traffic or cross-
traffic.
The PRE-SAFE ®
Brake may not detect narrow
vehicles driving in front of you, such as
motorcycles and vehicles driving offset from
your vehicle center.
GWarning!
Depending on the vehicle speed, the
PRE-SAFE ®
Brake brakes your vehicle with a
maximum of 13 ft/s 2
(4 m/s 2
) before a
possible hard stop. This corresponds to about
40% of the maximum deceleration ability of
your vehicle. The driver must apply the brakes
additionally in order to prevent a collision. The
self-acting hard stop will be initiated when the
imminent danger of a collision exists, e.g.
when an evasive driving maneuver cannot
avoid an accident.
The PRE-SAFE ®
Brake applies the brake pedal
automatically which results in the brake pedal
moving. Therefore keep driver’s foot area
clear at all times, including the area under the
brake pedal. Objects stored in this area may
impair pedal movement which could interfere
with the braking ability of the PRE-SAFE ®
Brake.
Do not place your foot under the brake pedal
– your foot could become caught.
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