2004 MERCEDES-BENZ S430 brake

68 Safety and SecurityOccupant safetyPreventive occupant safety (PRE-SAFE)
Your vehicle automatically takes preven-
tive measures to better protect the occu-
pants in the following hazardous
situations:

You execute an emergency braking ma-
neuver and the Brake Assist System
(page 78) is activated.


The PRE-SAFE system detects a critical
driving dynamics situation.In such cases, the following systems are
automatically activated:


A front seat belt with the seat belt
buckled is pre-tensioned electrically.


If the occupied front passenger seat or
rear seats are in an unfavorable posi-
tion, they are adjusted to a better posi-
tion. Rear seat adjustment occurs only
in vehicles with individual seats* in the
rear.


The sliding/pop-up roof closes if the
vehicle is in a severe skid or is spin-
ning.
If the seat belts do not release:

Adjust the backrest or seat slightly to
the rear until the seat belt tension is di-
minished.
The locking mechanism releases.
Warning
G
The PRE-SAFE system is intended to reduce
the effects of an accident on properly seat
belted vehicle occupants. Despite having
the PRE-SAFE systems in your car, the pos-
sibility of injuries occurring as a result of an
accident cannot be totally eliminated.
Therefore you should always drive carefully
and adjust your driving to the prevailing
road, weather, and traffic conditions.
iThe PRE-SAFE systems are activated in
the previously described circumstanc-
es only at speeds exceeding 22 mph
(35 km/h).
When the driving dynamic situation has
passed without an accident occurring,
the pre-tensioning on the seat belts is
deactivated.
You can then adjust the seats and the
sliding sunroof to their previous posi-
tion.

77 Safety and Security
Driving safety systems
Driving safety systems
In this section you will find information on
the following driving safety systems:

ABS (A
ntilock B
rake S
ystem)


BAS (B
rake A
ssist S
ystem)


ESP (E
lectronic S
tability P
rogram)


4MATIC (Four Wheel Electronic Trac-
tion System)
ABS
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 ap-
proximately 5 mph (8 km/h) independent
of road surface conditions.
On slippery road surfaces, the ABS will re-
spond even with light brake pressure.
iIn winter operation, the maximum ef-
fectiveness of the ABS, ESP, BAS and
4MATIC is only achieved with winter
tires (M + S tires) or snow chains as re-
quired.
Warning!
G
The following factors increase the risk of ac-
cidents:

Excessive speed, especially in turns


Wet and slippery road surfaces


Following another vehicle too closely
The ABS, BAS, ESP, and 4MATIC cannot re-
duce this risk.
Always adjust your driving style to the pre-
vailing road and weather conditions.
Warning!
G
Do not pump the brake pedal. Use firm,
steady brake pedal pressure instead. Pump-
ing the brake pedal defeats the purpose of
the ABS and significantly reduces braking
effectiveness.

78 Safety and SecurityDriving safety systemsThe - indicator lamp in the instrument
cluster comes on when you turn the
SmartKey in the starter switch to
position2 or press the KEYLESS-GO*
start/stop button twice. It goes out when
the engine is running.
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 303).
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.
Warning!
G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency be-
yond that afforded by the condition of the
vehicle brakes and tires or the traction af-
forded. The ABS cannot prevent accidents,
including those resulting from excessive
speed in turns, following another vehicle too
closely, or hydroplaning. Only a safe, atten-
tive, and skillful driver can prevent acci-
dents. The capabilities of an ABS equipped
vehicle must never be exploited in a reck-
less or dangerous manner which could jeop-
ardize the user’s safety or the safety of
others.

79 Safety and Security
Driving safety systems
ESP
The Electronic Stability Program (ESP)
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 engine output, the ESP works to
stabilize the vehicle. The ESP is especially
useful while driving off and on wet or slip-
pery road surfaces.
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 turn the
SmartKey in the starter switch to
position2 or press the KEYLESS-GO*
start/stop button twice. It goes out when
the engine is running.
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. The BAS cannot
prevent accidents, including those resulting
from excessive speed in turns, following an-
other vehicle too closely, or hydroplaning.
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 dangerous manner which
could jeopardize the user’s safety or the
safety of others.
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 resulting
from excessive speed.

80 Safety and SecurityDriving safety systems
For more information, see “Practical hints”
(page 303).Switching off the ESP
To improve the vehicle's traction, turn off
the ESP in driving situations where it would
be advantageous to have the drive wheels
spin and thus cut into surfaces for better
grip such as:


starting out on slippery surfaces and in
deep snow in conjunction with snow
chains


in sand or gravel
Warning!
G
The ESP cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase the traction afforded. The ESP
cannot prevent accidents, including those
resulting from excessive speed in turns, or
hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The ca-
pabilities of an ESP equipped vehicle must
never be exploited in a reckless or danger-
ous manner which could jeopardize the us-
er’s safety or the safety of others.!The ESP will only function properly if
you use wheels of the recommended
tire size (
page 384).
iDistronic* is switched off when ESP is
activated.
!Vehicles without 4MATIC:
Because of the ESP’s automatic opera-
tion, the engine and ignition must be
shut off (SmartKey in starter switch
position0 or1 or KEYLESS-GO
start/stop button* in position0 or1)
when:

the parking brake is being tested on
a brake test dynamometer


the vehicle is being towed with the
front/rear axle raised
Active braking action through the ESP
may otherwise seriously damage the
brake system.
For information on vehicles with
4MATIC, see “Four wheel electronic
traction system (4MATIC) with the
ESP” (
page 82).
Warning!
G
The ESP should not be switched off during
normal driving other than in the circum-
stances described below. Disabling of the
system will reduce vehicle stability in stan-
dard driving maneuvers.iDistronic* cannot be activated when
the ESP has been deactivated.

81 Safety and Security
Driving safety systems
The switch is located on the center con-
sole.
1ESP off / on
Press ESP switch1 until the ESP
warning lampv in the speedometer
comes on.
The ESP is deactivated.If one or more wheels are spinning, the
ESP warning lampv in the speedome-
ter flashes, regardless of the speed.
Traction control brakes a spinning wheel
even when the ESP is deactivated.
The ESP always operates when you are
braking, even when it has been deactivat-
ed.
Switching on the ESP

Press the ESP switch1.
The ESP warning lampv in the in-
strument cluster goes out. You are now
again in normal driving mode.
!Avoid spinning of a drive wheel for an
extended period with the ESP switched
off. This may cause serious damage to
the drivetrain which is not covered by
the Mercedes-Benz Limited Warranty.
Warning!
G
When the ESP warning lampv is
illuminated continuously, the ESP is
switched off.
Adapt your speed and driving to the prevail-
ing road conditions and to the non-operating
status of the ESP.

82 Safety and SecurityDriving safety systemsFour wheel electronic traction system (4MATIC) with the ESP
Models with all-wheel drive only:
The 4MATIC improves the vehicle’s ability
to use available traction, e.g. during winter
operation in mountains under snowy con-
ditions, by applying power to all four
wheels.
Warning!
G
If you see the ESP warning lamp v flash-
ing in the speedometer dial, 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 resulting
from excessive speed.!Do not tow with one axle raised.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.
!Performance testing must only be con-
ducted on a two-axle dynamometer.
Otherwise the transfer case can be
damaged, which is not covered by the
Mercedes-Benz Limited Warranty.!Because of the ESP’s automatic opera-
tion, the engine and ignition must be
shut off (SmartKey in starter switch
position0 or1 or KEYLESS-GO
start/stop button* in position0 or1)
when the parking brake is being tested
on a brake test dynamometer.
Active braking action through the ESP
may otherwise seriously damage the
front or rear axle brake system.
Operational tests with the engine run-
ning can only be conducted on a
two-axle dynamometer.

93 Controls in detail
Locking and unlocking


Never store the SmartKey with
KEYLESS-GO together with:

Electronic items such as a cellular
phone or another SmartKey with
KEYLESS-GO


Metallic objects such as coins or
metal foil
Doing so could impair the function of
the KEYLESS-GO system.


To lock or unlock the vehicle, the
SmartKey with KEYLESS-GO must be
located outside the vehicle within ap-
proximately 3 ft. (1 m) of a door or the
trunk.


In order to start the engine with the
SmartKey with KEYLESS-GO:

The SmartKey with KEYLESS-GO
must be located in the vehicle.


All doors must be closed.


The brake pedal must be firmly dep-
resed. Do not depress the accelera-
tor.


If you have started the engine with the
KEYLESS-GO start/stop button, you
can only turn it off again with this but-
ton, even if you have put the SmartKey
in the starter switch in the meantime.


This does not apply if, after starting, the
gear selector lever is still in positionP
and the SmartKey is then inserted in
the starter switch. The SmartKey will
then have priority over the SmartKey
with KEYLESS-GO and the vehicle’s
electrical system will operate accord-
ing to the position of the SmartKey in
the starter switch, even stopping the
engine.


If the SmartKey with KEYLESS-GO is
positioned farther away from the vehi-
cle, the system may no longer recog-
nize the SmartKey with KEYLESS-GO.
The vehicle then cannot be locked or
the engine started via the KEYLESS-GO
system.


If the SmartKey with KEYLESS-GO is re-
moved from the vehicle while the en-
gine is switched on (e.g. if passenger
exits the vehicle with the SmartKey
with KEYLESS-GO), the message
KEY
NOT RECOGNIZED!
will appear in the
multifunction display.
Find the SmartKey or change its
present location immediately
(e.g. place it on the front passenger
seat or insert it in shirt pocket).


Remember that the engine can be
started by anyone with a SmartKey
with KEYLESS-GO that is left inside the
vehicle. If you leave the SmartKey with-
KEYLESS-GO behind when exiting and
locking the vehicle, the message
KEY
DETECTED IN VEHICLE!
will appear in
the multifunction display.