2004 MERCEDES-BENZ CLK320 CABRIOLET ECU

76 Safety and SecurityDriving safety systems
Driving safety systemsIn 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)
iIn winter operation, the maximum ef-
fectiveness of the ABS, the BAS, and
the ESP 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, and ESP cannot reduce this
risk.
Always adjust your driving style to the pre-
vailing road and weather conditions.

77 Safety and Security
Driving safety systems
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.The - indicator lamp in the instrument
cluster (
page 22) 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.
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 systemsEmergency brake maneuver
Keep continuous full pressure on the
brake pedal.
For more information, see “Practical hints”
(
page 311).
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”
(page 311).
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. The
ABS cannot prevent accidents, including
those resulting from excessive speed in
turns, following another vehicle too closely,
or hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The ca-
pabilities of an ABS 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.
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.

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 warning lamp v 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.
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
follows:

While driving off, apply as little throttle
as possible.


While driving, ease upon 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.
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.iDistronic* is switched off when ESP is
activated.

80 Safety and SecurityDriving safety systemsFor more information, see “Practical hints”
(page 311).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


sand or gravel
The switch is located on the center con-
sole.1ESP off
2ESP on

Press upper half1 of the ESP switch
until the ESP warning lamp v in the
instrument cluster comes on.
The ESP is deactivated.
If one or more drive wheels are spinning,
the ESP warning lamp v in the instru-
ment cluster flashes, regardless of the
speed.
!Because of the ESP’s automatic opera-
tion, the engine must be shut off
(SmartKey in starter switch position0
or1 or KEYLESS-GO* start/stop but-
ton in position0 or1) when

the parking brake is being tested on
a brake test dynamometer


the vehicle is being towed with the
front axle raised
Active braking action through the ESP
may otherwise seriously damage the
brake system.
The ESP will only function properly if
you use wheels of the recommended
tire size.
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.

81 Safety and Security
Driving safety systems
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 lower half2 of the ESP switch
until the ESP warning lamp v in the
instrument 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 lamp
v
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 SecurityAnti-theft systems
Anti-theft systemsImmobilizer
The immobilizer prevents unauthorized
persons from starting your vehicle.
Activating

With the SmartKey: Removing the
SmartKey from the starter switch acti-
vates the immobilizer.


With KEYLESS-GO*: Turning off the en-
gine by means of the start/stop button
on the gear selector lever activates the
immobilizer.Deactivating


With the SmartKey: Inserting the
SmartKey in the starter switch deacti-
vates the immobilizer.


With KEYLESS-GO*: Starting the en-
gine by means of the start/stop button
on the gear selector lever deactivates
the immobilizer.
iIn case the engine cannot be started
(yet the vehicle’s battery is charged),
the system is not operational. Contact
an authorized Mercedes-Benz Center
or call 1-800-FOR-MERCedes (in the
USA), or 1-800-387-0100 (in Canada).

83 Safety and Security
Anti-theft systems
Anti-theft alarm system
Once the alarm system has been armed, a
visual and audible alarm is triggered when
someone opens

a door


the trunk


the hood.
The alarm will stay on, even if the activat-
ing element (a door, for example) is imme-
diately closed.The alarm system will also be triggered
when


someone attempts to raise the vehicle


the vehicle is opened with the mechan-
ical key.Arming the alarm system
The alarm system is armed after locking
the vehicle with the SmartKey or
KEYLESS-GO*. The turn signal lamps flash
three times to indicate that the alarm sys-
tem is activated. The indicator lamp in the
switch for the tow-away alarm will flash af-
ter approximately 30 seconds when the
alarm system is completely armed
(
page 25).
iIf the alarm stays on for more than
20 seconds, an emergency call is initi-
ated automatically by the Tele Aid sys-
tem (
page 257) provided Tele Aid
service was subscribed to and properly
activated, and that necessary cellular
service and GPS coverage are avail-
able.
iIf the turn signal lamps do not flash
three times one of the following ele-
ments may not be properly closed:

a door


the trunk lid
Close the respective element and lock
the vehicle again.