2008 MERCEDES-BENZ S550 4MATIC Emergency brakes

67 Safety and Security
Driving safety systems
Braking
At the instant one of the wheels is about to
lock up, a slight pulsation can be felt in the
brake pedal, indicating that the ABS is in
the regulating mode.
Keep firm and steady pressure on the
brake pedal while experiencing the pul-
sation.
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 indica-
tion of hazardous road conditions and
functions as a reminder to take extra care
while driving.
Emergency brake maneuver
Keep continuous full pressure on the
brake pedal.For more information, see “Practical hints”
(
page 598).
Adaptive Brake
Adaptive Brake provides a high level of
braking safety as well as increased braking
comfort. It is coupled with ABS, ESP
® and
BAS. Adaptive Brake takes driver and vehi-
cle characteristics into consideration, thus
achieving an optimal braking effect.
Warning!G
When the ABS is malfunctioning, the BAS,
BAS Plus* and ESP® are also switched off.
When the ABS is malfunctioning, the wheels
may lock during hard braking, reducing
steering capability and extending the brak-
ing distance.
Warning!G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency
beyond that afforded by the condition of the
vehicle brakes and tires or the traction
afforded. The ABS cannot prevent acci-
dents, including those resulting from exces-
sive speed in turns, following another
vehicle too closely, or hydroplaning.
Only a safe, attentive, and skillful driver can
prevent accidents.
The capabilities of an ABS equipped vehicle
must never be exploited in a reckless or dan-
gerous manner which could jeopardize the
user’s safety or the safety of others.

68 Safety and Security
Driving safety systems
Adaptive Brake Lights
(S 600/S 65 AMG and USA only)
The brake lamps flash in quick intervals
while you are braking in order to signal to
cars behind you that

you are braking strongly at a speed of
more than 30 mph (50 km/h)

you are braking with the aid of BAS or
BAS Plus*
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 automatically comes on as soon as
the vehicle is at a standstill. While the vehi-
cle is stationary, the brake lamps are con-
tinuously lit up.
Once you drive faster than 6 mph
(10 km/h) afterward, the hazard warning
flasher goes out.
BAS
The Brake Assist System (BAS) operates in
emergency situations. If you apply the
brakes very quickly, the BAS automatically
provides full brake boost, thereby poten-
tially reducing the braking distance.
Apply 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.
For more information, see “Practical hints”
section (
page 598).
Warning!G
When the BAS is malfunctioning, the brake
system is still functioning normally, but with-
out the additional brake boost available that
BAS would normally provide in an emergen-
cy braking maneuver. Therefore, the braking
distance may increase.
Warning!G
The BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that af-
forded by the condition of the vehicle brakes
and tires or the traction afforded. The BAS
cannot prevent accidents, including those
resulting from excessive speed in turns, fol-
lowing another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful
driver can prevent accidents.
The capabilities of a BAS equipped vehicle
must never be exploited in a reckless or dan-
gerous manner which could jeopardize the
user’s safety or the safety of others.

69 Safety and Security
Driving safety systems
BAS Plus*
The Brake Assist System Plus (BAS Plus)
operates in emergency braking situations
and uses radar sensors* to assess the traf-
fic situation. BAS Plus assists you in brak-
ing at speeds above approximately 20 mph
(30 km/h).
When travelling in Canada in a vehicle not
registered in Canada, you must switch off
the radar sensor system* (
page 282).
Canadian law does not permit the use of
the radar sensor system* (
page 282) for
vehicles from outside of Canada. When you
switch off the radar sensor system*, the
following functions are deactivated:

BAS Plus

DISTRONIC Plus* (page 424)

Park Assist* (page 448)

PRE-SAFE® Brake* (page 76)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 driv-
er applies the brakes.
iUSA 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 de-
vice 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.
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 re-
ceived, 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.
Warning!G
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. Other-
wise, you may not be able to recognize
dangerous situations until it is too late and
could cause an accident resulting in person-
al or fatal injury to you or others.

70 Safety and Security
Driving safety systems
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 suit-
able for the traffic situation.
If BAS Plus requires a particularly high
brake power boost, PRE-SAFE
® is activat-
ed at the same time.
Keep constant pressure on the brake
pedal until the emergency braking situ-
ation is over.
During this process, ABS prevents the
wheels from locking up.
The brakes will resume normal operation
after

the brake pedal is released

no obstacles are detected in your path

the system no longer senses a risk of a
collision
BAS Plus is 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 func-
tional. You can check whether the sensors
are active by switching on DISTRONIC
Plus* (
page 424) or using the “Radar
sensor” menu (
page 282) in the instru-
ment cluster control system.
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.
Warning!G
BAS Plus will only respond with brake assis-
tance if it has clearly detected an object. De-
tection can be impeded by

dirty or covered sensors

snowfall or heavy rain

disturbance from other radar sources

strong radar reflection such as in park-
ing garages
BAS Plus uses radar signals that are not re-
flected well by narrow objects and absorp-
tive materials. For this reason BAS Plus will
not react to

persons and animals

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.

71 Safety and Security
Driving safety systems
EBP
The Electronic Brake Proportioning (EBP)
enhances braking effectiveness by allow-
ing the rear brakes to supply a greater pro-
portion of the braking effort in straight line
braking without a loss of vehicle stability.ESP®
The Electronic Stability Program (ESP®) is
operational as soon as the engine is run-
ning and monitors the vehicle’s traction
(force of adhesive friction between the
tires and the road surface) and handling.
The ESP
® recognizes when a wheel is spin-
ning or if the vehicle starts to skid. By ap-
plying brakes to the appropriate wheel and
by limiting the engine output, the ESP
®
works to stabilize the vehicle. The ESP® is
especially useful while driving off and on
wet or slippery road surfaces. The ESP
®
also stabilizes the vehicle during braking
and steering maneuvers.
The ESP
® warning lamp v in the instru-
ment cluster flashes when the ESP® is en-
gaged.
The ESP
® warning lamp v in the instru-
ment cluster comes on when you switch on
the ignition (
page 344). It goes out when
the engine is running.
Warning!G
When the EBP is malfunctioning, the ABS,
BAS, BAS Plus* and ESP® are also switched
off.
If the EBP is malfunctioning, the brake sys-
tem will still function with full brake boost.
However, the rear wheels could lock up dur-
ing emergency braking situations, for exam-
ple. You could lose control of the vehicle and
cause an accident. Adapt your driving style
to the changed driving characteristics.
Warning!G
Never switch off the ESP® when you see the
ESP® warning lamp v flashing in the in-
strument cluster. In this case proceed as fol-
lows:

While driving off, apply as little throttle
as possible.

While driving, ease up on the accelera-
tor.

Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The ESP
® cannot prevent accidents result-
ing from excessive speed.

79 Safety and Security
Driving safety systems
To maintain the proper distance to the ve-
hicle in front of you and thus prevent a
rear-end collision, you must apply the
brakes yourself.
Immediately brake the vehicle to avoid
a collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking. See the follow-
ing warning note.
The intermittent warning sound ceases
and the distance warning lampl
goes out when the necessary distance
to the vehicle ahead is again
established.PRE-SAFE
® Brake can react to stationary
obstacles such as standing or parked vehi-
cles at road speeds of up to approximately
40 mph (70 km/h).
Activating and deactivating: Activate
or deactivate PRE-SAFE® Brake using
the instrument cluster control system
(
page 279).
After the function has been activated,
indicator : appears on the
left-hand side of the multifunction dis-
play.
Warning!G
An intermittent warning sounds and the dis-
tance warning lampl in the instrument
cluster is illuminated if PRE-SAFE
® Brake
calculates that the distance to the vehicle
ahead and your vehicle’s current speed indi-
cate that PRE-SAFE
® Brake will not be capa-
ble 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 situ-
ation. Do not wait for the operation of the
warning signal to intercede with your own
braking, as that will result in potentially dan-
gerous emergency braking which will not al-
ways result in an impact being avoided.
Tailgating increases the risk of an accident.
Warning!G
If you do not receive visual or acoustic warn-
ing signals, PRE-SAFE® Brake has either not
recognized the collision risk, has been deac-
tivated or is malfunctioning. Apply the
brakes yourself to avoid a collision.

428 Controls in detail
Driving systems
Displaying the distance graphic
In the “Assistance” menu under “Distance
display” you see the current settings for
DISTRONIC Plus. The information shown in
the multifunction display depends on
whether DISTRONIC Plus is activated or
deactivated.
vehicle ahead and your vehicle’s current
speed indicate that DISTRONIC Plus 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 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 sig-
nal to intercede with your own braking, as
that will result in potentially dangerous
emergency braking which will not always re-
sult in an impact being avoided.
Tailgating increases the risk of an accident.
Warning!G
DISTRONIC Plus brakes your vehicle with a
maximum of 13 ft/s2. This corresponds to
about 40% of the maximum deceleration
ability of your vehicle.
You must also apply the brakes yourself to
avoid a collision. DISTRONIC Plus brakes
the vehicle in an effort to restore the preset
distance or to maintain the speed. The brake
pedal is automatically applied as this hap-
pens which results in the brake pedal mov-
ing.
Keep driver’s foot area clear at all times, in-
cluding the area under the brake pedal. Ob-
jects stored in this area may impair pedal
movement which could interfere with the
braking ability of the DISTRONIC Plus sys-
tem.
Do not place your foot under the brake pedal
– your foot could become caught.Warning!G
If you do not receive visual or acoustic warn-
ing signals during a critical traffic situation,
DISTRONIC Plus has either not recognized
the collision risk, has been deactivated or is
malfunctioning.
Remember, whether or not DISTRONIC Plus
is operating, it is ultimately always the driv-
ers responsibility to apply the brakes in or-
der to control the vehicle and avoid a
collision.
iFor activating or deactivating the
DISTRONIC Plus system, see “Activating
DISTRONIC Plus” (
page 430) or “Deactivating
DISTRONIC Plus” (
page 435).