2003 MERCEDES-BENZ SL500 overheat

74 Safety and SecurityDriving safety systems
The SBC brake servo assistance switches
off automatically when you

remove the key from the starter switch
(after approximately two minutes)


lock the vehicle (after approximately
20 seconds)
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
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 key in the starter switch
is turned to position1, when the brake ped-
al is depressed or when the parking brake is
released. Failure to deactivate the system
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which
may result in injuries (contusions and acid
burns). Extended brake pistons may also
cause injury.
Warning!
G
Be very careful not to endanger other road
users when you apply the brakes.

216 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 In such a case, the red
brake warning lamp (
page 253) and warn-
ing messages (
page 265) in the instru-
ment cluster light up while driving. To brake,
the driver must then apply significantly
greater brake pedal pressure and depress
the pedal much further to obtain the expect-
ed braking effect. If necessary, apply full
pressure to the brake pedal. Brakes are only
applied to the front wheels. Stopping dis-
tance is increased! 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 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, refer to "Towing the vehicle"
(page 325).
With the engine not running, there is no
power assistance for the steering system. In
this case, it is important to keep in mind that
a considerably higher degree of effort is nec-
essary to steer the vehicle.
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.

217 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 72) 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 at an au-
thorized Mercedes-Benz Center immedi-
ately.
All checks and service work on the brake
system should be carried out by an autho-
rized 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 69).
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 74).
!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.

223 Operation
Driving instructions
Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected to an antenna that is installed on
the outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external an-
tenna.
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Service Booklet.
Warning!
G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.
!To prevent damage to the catalytic con-
verters, only use premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter caus-
ing it to overheat, which could start a
fire.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble 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.

224 OperationDriving instructionsEmission control
Certain systems of the engine serve to
keep the toxic components of the exhaust
gases within permissible limits required by
law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments on the engine should therefore
be carried out only by qualified
Mercedes-Benz Center authorized techni-
cians. Engine adjustments should not be
altered in any way. Moreover, the specified
service jobs must be carried out regularly
according to Mercedes-Benz servicing re-
quirements. For details refer to the Service
Booklet.
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to approx. 266°F
(130°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide, and inhaling it can cause uncon-
sciousness and lead to death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated. If you think that exhaust gas
fumes are entering the vehicle while driving,
have the cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one win-
dow fully open at all times.
Warning!
G


Driving when your engine is badly over-
heated can cause some fluids, which
may have leaked into the engine com-
partment, to catch fire. You could be se-
riously burned.


Steam from an overheated engine can
cause serious burns and can occur just
by opening the engine hood. Stay away
f r o m t h e e n g i n e i f y o u s e e o r h e a r s t e a m
coming from it. Turn off the engine, get
out of the vehicle and do not stand near
the vehicle until it cools down.

228 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1
1/2ft (50 cm).
The hood will lock audibly.

Check to make sure that the hood is
fully closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when

the vehicle is new


the vehicle is driven frequently at high-
er engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Checking engine oil level
When checking the oil level the vehicle
must


be parked on level ground


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from the vehicle and do not open the
hood until the engine has cooled. If neces-
sary, call the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition coils, spark plug sockets, diagnostic
socket) of the ignition system

with the engine running


while starting the engine


if ignition is “on” and the engine is
turned manually
Warning!
G
Be careful that you do not close the hood on
anyone.

231 Operation
Engine compartment
1Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.

Continue turning the cap to the left and
remove it.
The coolant level is correct if the level


for cold coolant: is up to the upper
mark on the bracing rib of the coolant
expansion tank (translucent)


for warm coolant: is approx. 0.6 in
(1.5 cm) higher

Add coolant as required.

Replace and tighten cap.
More information on coolant can be found
in the “Technical data” section
(
page 345).
Warning!
G
In order to avoid any possibly serious burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if engine temperature is above
194°F (90°C). Allow engine to cool
down before removing cap. The coolant
reservoir contains hot fluid and is under
pressure.


Using a rag, slowly open the cap approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.

237 Operation
Tires and wheels
Activating the tire inflation pressure
monitor
You must activate the tire inflation pres-
sure monitor in the following cases:

if you have changed the tire pressure


if you have replaced the wheels or tires


if you have installed new wheels or
tires

Be sure that the tire pressure is cor-
rectly set.

Press the
k
button until the infla-
tion pressure of each tire appears in
the right display field.

Press the reset knob (
page 21).
The following message will appear in
the speedometer display field:
Monitor current tire pressure?


Press
æ
button.
The following message will appear in
the speedometer display field:
Tire pressure monitor activated!

Pressure display after driving
several mins.
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.
iIf transporting a deflated road wheel or
additional wheel sensors in the vehicle,
the tire inflation pressure monitor
should not be reactivated until the de-
flated wheel or additional wheel sen-
sors have been removed from the
vehicle. Otherwise, the deflated wheel
or additional sensors could confuse the
tire inflation pressure monitor system
and cause it to malfunction.