2004 MERCEDES-BENZ SL500 ECU

77 Safety and Security
Driving safety systems
For more information, see the
“Practical hints” section (
page 282).
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 potential-
ly 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. 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
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.

78 Safety and SecurityDriving safety systemsESP
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 ABS/ESP warning lamp v in the in-
strument cluster (
page 23) flashes when
the ESP is engaged.
The ABS/ESP warning lamp v in the in-
strument cluster (page 23) 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
ABS/ESP warning lamp
v
flashing in the
instrument cluster. In this case proceed as
follows:


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.
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 the ESP
is engaged.

79 Safety and Security
Driving safety systems
For more information, see the
“Practical hints” section (
page 282).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 gravelThe switch is located in the lower part of
the center console.
1ESP switch

Press ESP switch1 until the ABS/ESP
warning lamp v in the instrument
cluster comes on.
ESP is deactivated.
!Because of the ESP’s automatic opera-
tion, the engine must be shut off
(SmartKey in starter switch position 0
or 1 or KEYLESS-GO* start/stop but-
ton in position 0 or 1) 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.
The ESP will only function properly if
you use wheels of the recommended
tire size (
page 378).
Warning!
G
ESP should not be switched off during nor-
mal driving other than in the circumstances
described below. Disabling of the system
will reduce vehicle stability in standard driv-
ing maneuvers.!Turn on the ESP immediately if the
aforementioned circumstances do not
apply anymore.
iDistronic* cannot be activated when
the ESP has been deactivated.


80 Safety and SecurityDriving safety systemsIf one or more drive wheels are spinning,
the ABS/ESP warning lamp v in the in-
strument cluster 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 ESP switch1.
The ABS/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 ABS/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.


81 Safety and Security
Driving safety systems
SBC brake system
The SBC brake system combines a hydrau-
lic brake circuit with electronically con-
trolled brake servo assistance. You have
increased braking safety and improved
braking comfort.Warning!
G
Never ignore a brake malfunction indicated
in the speedometer display, for example by
the
;
(USA only) or
3
(Canada only)
indicator lamp. Refer to the “Practical hints”
section (
page 284). Also read and ob-
serve the messages in the instrument clus-
ter multifunction display (
page 299).
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 284)
comes on and warning messages
(
page 299) appear in the multifunction
display while driving. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is in-
creased!
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate wheel lift/dolly
equipment.
A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
up to 30 miles (50 km) and at a speed not to
exceed 30 mph (50 km/h). For more infor-
mation, see “Towing the vehicle”
(page 365).

82 Safety and SecurityDriving safety systemsThe SBC brake system is automatically ac-
tivated when you

unlock the vehicle with the SmartKey
or the SmartKey with KEYLESS-GO*


open the driver’s or passenger door


turn the SmartKey in the starter switch
to position1


in vehicles with KEYLESS-GO*, press
start/stop button on gear selector le-
ver once


depress the brake pedal


release the parking brake
iIf the SBC brake system is activated as
the brake pedal is first depressed, you
may feel a reduced pedal resistance
and longer pedal travel than normal.
When releasing the pedal, you may also
feel the brake pedal pulsate and you
may hear a sound which is caused by
the activation of the SBC pump. This is
normal and not an indication of a mal-
function. Pedal travel returns to normal
when you release the brake pedal and
the sound soon ceases.
If you experience the above while driv-
ing and the red brake warning lamp
(page 284) illuminates and/or warn-
ing messages appear in the multifunc-
tion display (
page 299), the brake
system is malfunctioning. Follow the in-
structions of the warning message(s)
and have the brake system checked
immediately.
Warning!
G
Have brake pad replacement and other work
on the SBC brake system carried out by
qualified technicians only. Contact your
Mercedes-Benz Center for further informa-
tion. The SBC brake system must be deacti-
vated prior to working on the system. High
pressure is intermittently built up in the sys-
tem as part of its automatic self-test. In ad-
dition, the system is automatically activated
when the vehicle is unlocked by remote con-
trol, when the driver or passenger door is
opened, when the SmartKey in the starter
switch is turned to position1 or the
KEYLESS-GO* start/stop button is pressed
once, when the brake pedal is depressed or
when the parking brake is released. Failure
to deactivate the system prior to mainte-
nance will cause brake pistons to extend
and brake fluid to leak, which may result in
injuries (contusions and acid burns). Extend-
ed brake pistons may also cause injury.

83 Safety and Security
Driving safety systems
The SBC brake servo assistance switches
off automatically

approximately two minutes after you
turned the SmartKey in the starter
switch to position0 or removed the
SmartKey


approximately two minutes after you
pressed the KEYLESS-GO* start/stop
button to turn off the engine or power
supply and opened the driver’s door
(with driver’s door open, the starter
switch is set to position 0, same as
SmartKey removed from starter
switch)


approximately 20 seconds after you
locked the vehicle from outside Note on driving with SBC


Following extended periods of only mi-
nor loads to your brake system, you
should occasionally apply the brakes
when traveling at high speeds. This im-
proves the grip of the brake pads.
After driving on wet or snow-covered
roads, you should apply your brakes
firmly before parking your vehicle. This
produces heat which serves to dry the
brake disks and help prevent corro-
sion.


On long and steep grades, shift to a
lower gear (gear range1, 2, or 3) to
prevent the brakes from overheating
and to reduce brake wear.


After hard braking, it is advisable to
drive on for some time so that the air
stream will cool down the brakes fast-
er.


Only Mercedes-Benz approved compo-
nents (e.g. brake pads) should be in-
stalled on your vehicle. Brake pads not
approved by Mercedes-Benz may im-
pair the safety of your vehicle.
Warning!
G
Be very careful not to endanger other road
users when you apply the brakes.

84 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).