2005 MERCEDES-BENZ SLR CLASS four wheel drive

85 Safety and Security
Driving safety systems
The SBC brake system is automatically ac-
tivated when you

unlock the vehicle with the SmartKey


open the driver’s or passenger door


turn the SmartKey in the starter switch
to position1


depress the brake pedal


release the parking brake
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
u p t o 3 0 m i l e s ( 5 0 k m ) a n d a t a s p e e d n o t t o
exceed 30 mph (50 km/h). For more infor-
mation, see “Towing the vehicle”
(page 357).
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 298) illuminates and/or warn-
ing messages appear in the multifunc-
tion display (
page 312), 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, when the
brake pedal is depressed or when the park-
ing brake is released. Failure to deactivate
the system prior to maintenance will cause
brake pistons to extend and brake fluid to
leak, which may result in injuries (contu-
sions and acid burns). Extended brake
pistons may also cause injury.

230 OperationDriving instructionsPower assistance
Brakes
Warning!
G
The brake system requires electrical energy
for operation.
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 298) and
warning messages (
page 304) in the in-
strument cluster come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes are
only applied to the front wheels. Stopping
distance is increased! If there is a malfunc-
tion in the SBC brake system, we recom-
mend that the vehicle be transported with
all wheels off the ground using flatbed or ap-
propriate 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 357).
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.

234 OperationDriving instructionsHydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.
Mercedes-Benz recommends M+S rated
radial-ply tires with a minimum tread depth
of approximately
1/6in (4 mm) on all four
wheels for the winter season to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance compared to summer
tires. Stopping distance, however, is still considerably greater than when the road is
not covered with snow or ice. Exercise ap-
propriate caution.
Tire speed rating
Regardless of the tire speed rating, local
speed limits should be obeyed. Use
prudent driving speeds appropriate to
prevailing conditions.
Warning!
G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
!Avoid spinning of a drive wheel. This
may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.

265 Operation
Tires and wheels
Checking tire inflation pressure
electronically
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is is-
sued to alert you to a decrease in pressure
in one or more of the tires.
Tire inflation pressure inquiries are made
using the multifunction display
(page 117). The present inflation pres-
sures are displayed only after a few min-
utes travel time.

Switch on the ignition (
page 40).

Make sure you are viewing the stan-
dard display menu (
page 117).

Press k button until the current in-
flation pressures for each tire appear in
the tachometer display field.
iPossible differences between the read-
ings of a tire inflation pressure gauge of
an air hose, e.g. gas station equipment,
and the vehicle’s control system can
occur. The readings issued by the con-
trol system are more precise.
iYou can select the unit of measure
(bar/psi) used for the tire inflation
pressure by changing the setting in the
control system (
page 136).
Warning!
G
When the tire inflation pressure monitoring
system warning light is lit, one or more of
your tires is significantly under-inflated. You
should stop and check your tires as soon as
possible, and inflate them to the proper tire
inflation pressure as indicated on the vehi-
cle’s tire information placard. Driving on a
significantly under-inflated tire causes the
tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Each tire,
including the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation pressure as specified
in the vehicle placard and owner’s manual.


284 OperationWinter drivingBefore the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing temperatures
(page 382).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started,
even at low ambient temperatures.


Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6in (4 mm) on all four wheels for the
winter season.
Winter tires*
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum
effectiveness of the ABS and ESP in winter
operation.
For safe handling, make sure that all
mounted winter tires are of the same make
and have the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available from your tire
dealer or from any authorized
Mercedes-Benz Center.
!A wheel change should only be carried
out at an authorized Mercedes-Benz
Center. Otherwise there is a danger of
damaging the vehicle by jacking it up
incorrectly.Warning!
G
Winter tires with a tread depth under
1/6in
(4 mm) must be replaced. They are no
longer suitable for winter operation.

313 Practical hints
What to do if ...
Left display
Right display
Possible cause
Possible solution
;
(USA only)
3
(Canada only)
Reduced
brake effect
Visit
workshop!
The SBC brake system is
in emergency operation
mode. Considerable
brake pedal force is re-
quired and the stopping
distance is increased.

Continue driving with added caution.

Visit an authorized Mercedes-Benz Center immedi-
ately. Adjust driving to be consistent with reduced
braking responsiveness.
Failure to follow these instructions increases the risk of
an accident.
Increased
braking distance
Visit
workshop!
Warning!
G
Driving while these messages are displayed
can result in an accident. Have your brake
system checked immediately.
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 357).
If the SBC brake system enters its emergen-
cy operation mode, the driver must apply
significantly greater brake pedal pressure
and depress the pedal much further than
normal to obtain braking effect.
If necessary, apply full pressure to the brake
pedal. Stopping distance is increased!