brakes MERCEDES-BENZ SL55AMG 2004 R230 User Guide

210 Controls in detailDriving systemsParktronic* (Parking assist)
The Parktronic system is an electronic aid
designed to assist the driver during park-
ing maneuvers. It visually and audibly indi-
cates the relative distance between the
vehicle and an obstacle.
The Parktronic system is automatically ac-
tivated when you switch on the ignition
and release the parking brake. The Park-
tronic system deactivates at speeds above
11 mph (18 km/h). At lower speeds the
Parktronic system turns on again.The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperWarning!
G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors, es-
pecially at times of snow and ice. See
“Cleaning the Parktronic* system sensors”
(page 277).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers or the air
brakes of trucks) can cause the system to
send erratic indications, and should be tak-
en into consideration.
Warning!
G
Make sure that no persons or animals are in
the area in which you are maneuvering. Oth-
erwise you run the risk of causing injury.

211 Controls in detail
Driving systems
Range of the sensors
To function properly, the sensors must be
free of dirt, ice snow and slush. Clean the
sensors regularly, being careful not to
scratch or damage the sensors.
Front sensors
Rear sensorsMinimum distance
If you encounter an obstacle in this range,
all the warning lamps come on and you
hear a warning signal. If the obstacle is
closer than the minimum distance, the ac-
tual distance may no longer be indicated
by the system.Warning indicators
Visual signals indicate to the driver the rel-
ative distance between the sensors and an
obstacle. The warning indicator for the
front area is located above the center air
vents in the dashboard. The warning indi-
cator for the rear area is integrated in the
rear trim.
Front area warning indicator1Left side of the vehicle
2Right side of the vehicle
Center
approx. 39 in (100 cm)
Corners
approx. 48 in (120 cm)
Center
approx. 48 in (120 cm)
Corners
approx. 32 in (80 cm)
!During parking maneuvers, pay special
attention to objects located above or
below the height of the sensors (e.g.
planters or trailer hitches). The Park-
tronic system will not detect such ob-
jects at close range and damage to
your vehicle or the object may result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes or jackham-
mers) may impair the operation of the
Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)

240 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 284) and
warning messages (
page 291) 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 365).
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.

241 Operation
Driving instructions
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.
If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on, there is a malfunction in the
SBC brake system (
page 81) or the
brake fluid level in the reservoir is too low.Brake pad wear or a leak in the system may
be the reason for low brake fluid in the res-
ervoir.
Have the brake system inspected immedi-
ately.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid rec-
ommended by Mercedes-Benz.After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so the air stream will cool down
the brakes faster.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS) (
page 77).
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
Be certain to read and observe the warning
notices on brake pad replacement
(page 82).
!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps pre-
vent overheating of the brakes and re-
duces brake pad wear.

242 OperationDriving instructionsDriving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
When starting off on a slippery surface, do
not allow a drive wheel to spin for an ex-
tended period with the ESP switched off.
Doing so may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Parking
!Simultaneously depressing the acceler-
ator pedal and applying the brake re-
duces engine performance and causes
premature brake and drivetrain wear.
Warning!
G
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
To reduce the risk of personal injury as a re-
sult of vehicle movement, before
turning off
the engine and leaving the vehicle always:


Keep right foot on brake pedal.


Firmly depress parking brake pedal.


Move the gear selector lever to
positionP.


Slowly release brake pedal.


When parked on an incline, turn front
wheels towards the road curb.


Turn the SmartKey to starter switch
position0 and remove, or press
KEYLESS-GO* start/stop button (vehi-
cles with KEYLESS-GO*).


Take the SmartKey or the SmartKey with
KEYLESS-GO* and lock vehicle when
leaving!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, turn front wheels
towards the road curb.

243 Operation
Driving instructions
Tires
Tread wear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and be-
come visible at a tread depth of approxi-
mately
1/16
in (1.6 mm), at which point
the tire is considered worn and should be
replaced.The tread wear indicator appears as a solid
band across the tread.
Specified tire pressures must be main-
tained. This applies particularly if the tires
are subjected to extreme operating condi-
tions (e.g. high speeds, heavy loads, high
ambient temperatures).
Hydroplaning
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.
Warning!
G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have it towed to the nearest
Mercedes-Benz Center or tire dealer for re-
pairs.
Warning!
G
Although the applicable federal motor vehi-
cle safety laws consider a tire to be worn
when the tread wear indicators (TWI) be-
come visible at approximately
1/16in
(1.6 mm), we recommend that you do not al-
low your tires to wear down to that level. As
tread depth approaches
1/8in (3 mm), the
adhesion properties on a wet road are
sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.

262 OperationTires and wheels
Tires and wheelsSee an authorized Mercedes-Benz Center
for information on tested and recommend-
ed rims and tires for summer and winter
operation. They can also offer advice con-
cerning tire service and purchase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See an authorized Mercedes-Benz Center
for information on tested and recommend-
ed rims and tires for summer and winter
operation.
Important guidelines

Only use sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire pressure loss or damage the
tire beads.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires is no longer guaran-
teed.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and may lead to
an accident.

265 Operation
Tires and wheels

Switch on ignition.

Make sure you are viewing the stan-
dard display menu (
page 127).

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 pressure gauge of an air
hose, e.g. gas station equipment, and
the vehicle’s control system can occur.
The readings issued by the control sys-
tem are more precise.
Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected in-
flation pressures. Always adjust tire inflation
pressure according to the label on the fuel
filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden dra-
matic loss of pressure (e.g. tire blowout
caused by a foreign object). In the event of
a sudden loss of pressure, bring the vehicle
to a halt by carefully applying the brakes and
avoiding abrupt steering maneuvers.
Warning!
G
Follow recommend tire pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure moni-
tor to malfunction.

287 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
E
The red DTR indicator lamp
comes on while driving.
You are too close to the vehicle in front of you
to maintain selected speed.

Apply the brakes immediately to in-
crease the following distance.
E
The red DTR indicator lamp
comes on while driving and you
hear a warning sound.


You are gaining too rapidly on the vehicle
ahead of you.


The distance warning system has recog-
nized a stationary obstacle on your prob-
able line of travel.

Apply the brakes immediately.

Carefully observe the traffic situation.
You may need to brake or maneuver
to avoid hitting an obstacle.
E
The white DTR indicator lamp
comes on while driving.
The Distronic* distance sensor has recog-
nized a vehicle in front of you.
A
The yellow fuel tank reserve
warning lamp lights while driv-
ing.
The fuel level has dropped below the reserve
mark.

Refuel at the next gas station
(page 250).
The fuel cap is not closed tight.

Check the fuel cap (
page 250).

300 Practical hintsWhat to do if …Left display
Right display
Possible cause
Possible solution
Except Canada:;Canada only:3
Reduced
brake effect
Visit workshop!
The SBC brake system is in emer-
gency operation mode. Consider-
able brake pedal force is required
and the stopping distance is in-
creased.

Continue driving with added caution.

Visit an authorized Mercedes-Benz Center im-
mediately. Adjust driving to be consistent
with reduced braking responsiveness.
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 365).
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. Brakes are only applied to the front
wheels. Stopping distance is increased!