engine MERCEDES-BENZ SLR CLASS 2007 Repair Manual

236 Operation
Driving instructions
Power assistanceBrakes
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 303) and
warning messages (
page 314) 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 electro-hydraulic brake system,
we recommend that the vehicle be trans-
ported 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 370).
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
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
effect. 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
accident.

237 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.
Refer to the description of the Brake Assist
System (BAS) (
page 83).If the parking brake is released and the red
brake warning lamp in the instrument clus-
ter stays on, there is a malfunction in the
electro-hydraulic brake system
(
page 303) 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
reservoir.
The brake fluid level in the reservoir may
be too low if the brake warning lamp in the
instrument cluster comes on and a warn-
ing sounds although the parking brake is
released (
page 303). Observe additional
messages that may appear in the
multifunction display (
page 330).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
!Because the ESP® operates automatically,
the engine must be shut off (SmartKey in starter
switch position 0 or1) when

the parking brake is being tested on a brake
test dynamometer

the vehicle is towed with the front axle raised
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iThe brake system is designed to decelerate
your SLR from high speeds at the best possible
rate. Depending on the applied brake force,
speed, and ambient conditions, the brake sys-
tem may produce a squeak-type noise when you
apply the brakes at a moderate rate, e.g. at city
traffic. If you experience this noise, you should
occasionally test the effectiveness of the brakes
by applying above-normal braking pressure at
high speeds. Please perform this braking proce-
dure three times. This will also enhance the grip
of the brake pads. If the noise continuous,
contact an authorized Mercedes-Benz Center.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.

238 Operation
Driving instructions
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than to park im-
mediately, so the air stream will cool down
the brakes faster.High performance driving
The rate of wear of individual brake system
components, such as brake pads or disks,
depends on your driving style and the con-
ditions under which you operate the vehi-
cle.
It is therefore not possible to give a gener-
ally applicable service life. High perfor-
mance driving, such as driving on closed
circuit race tracks or an aggressive driving
style, will cause the brakes to wear more
quickly.
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 88).
!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 prevent overheating of the brakes and
reduces brake pad wear.
iPlease contact your PLM or any authorized
Mercedes-Benz Center before operating the
vehicle under such demanding operating condi-
tions for more information.
Warning!G
Repetitive excessive load on the brake
system may particularly cause the brake
system to overheat and can thus reduce the
braking power, or even cause brake system
components to fail due to increased wear.
You could lose control of the vehicle and
cause an accident. Installation and examina-
tion of brake system assemblies requires
specialist knowledge. Therefore, after high
performance driving, have the brake system
checked and maintained by an authorized
Mercedes-Benz Center.

239 Operation
Driving instructions
Driving 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
operating temperature has been reached
(
page 307).
Parking
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
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.
!Simultaneously depressing the accelerator
pedal and applying the brakes reduces 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 or
damage to the vehicle drivetrain as a result
of vehicle movement, before turning off the
engine and leaving the vehicle always:

Keep right foot on brake pedal.

Pull the parking brake lever up as many
notches as possible.

Move the gear selector lever to park
positionP.

Slowly release brake pedal.

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

Turn the SmartKey in the starter switch
to position0 and remove.

Take the SmartKey with you and lock
vehicle when leaving.

242 Operation
Driving instructions
Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
move gear selector lever to neutral
positionN. Try to keep the vehicle under
control by corrective steering action.Road salts and chemicals can adversely
affect braking efficiency. Increased pedal
force may become necessary to produce
the normal braking effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
If the vehicle is parked after being driven
on salt-treated roads, the braking
efficiency should be tested as soon as
possible after driving is resumed.
For more information, see “Winter driving”
(
page 290).
iFor information on driving with snow chains,
see “Snow chains” (
page 291).
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced
vehicle control. Your vehicle’s ABS will not
prevent this type of control loss.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Warning!G
If the vehicle becomes stuck in snow, make
sure snow is kept clear of the exhaust pipe
and from around the vehicle with the engine
running. Otherwise deadly carbon monoxide
(CO) gases may enter vehicle interior
resulting in unconsciousness and death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the
vehicle not facing the wind.
Warning!G
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the
road surface is free of ice.

243 Operation
Driving instructions
Standing waterPassenger compartment
Driving abroad
Abroad, there is an extensive
Mercedes-Benz service network at your
disposal. If you plan to drive into areas
which are not listed in the index of your
Mercedes-Benz Center directory, you
should request pertinent information from
an authorized Mercedes-Benz Center.Control and operation of radio
transmitters
Radio and telephone
!Do not drive through flooded areas or water
of unknown depth. Before driving through water,
determine its depth. Never accelerate before
driving into water. The bow wave could force
water into the engine and auxiliary equipment,
thus damaging them.
If you must drive through standing water, drive
slowly to prevent water from entering the pas-
senger compartment or the engine compart-
ment. Water in these areas could cause damage
to electrical components or wiring of the engine
or transmission, or could result in water being in-
gested by the engine through the air intake caus-
ing severe internal engine damage. Any such
damage is not covered by the Mercedes-Benz
Limited Warranty.
Warning!G
Always fasten items being carried as
securely as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The trunk is the preferred place to carry
objects.
Warning!G
Please do not forget that your primary
responsibility is to drive the vehicle safely.
Only operate the radio or telephone
1 if road,
weather and traffic conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h), your vehicle is
covering a distance of 44 feet
(approximately 14 m) every second.
1Observe all legal requirements.

244 Operation
Driving instructions
Telephones and two-way radios
Radio transmitters, such as a portable
telephone or a citizens band unit should
only be used inside the vehicle if they are
connected to an antenna that is installed
on the outside of the vehicle.
Refer to the radio transmitter operation
instructions regarding use of an external
antenna.Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial
control of the pollutants in the exhaust
emissions. Keep your vehicle in proper
operating condition by following our
recommended maintenance instructions
as outlined in your Maintenance 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,
possibly resulting in an accident and
personal injury.
!To prevent damage to the catalytic
converters, only use premium unleaded gasoline
in this vehicle.
Any noticeable irregularities in engine operation
should be repaired promptly. Otherwise exces-
sive unburned fuel may reach the catalytic
converter, causing it to overheat and potentially
start a fire.
Warning!G
As with any vehicle, do not idle, park or
operate this vehicle in areas where combus-
tible 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.
Warning!G
The exhaust areas on the engine hood and
between the doors and front wheels get very
hot. Avoid contact with them, otherwise
there is the risk of severe burns.

245 Operation
Driving instructions
Emission 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
according to factory specifications. Any
adjustments 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
requirements. For details refer to the
Maintenance Booklet.Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant
temperature may rise close to
approximately 248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious
engine 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 (CO), and inhaling it can cause
unconsciousness and possible 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
window fully open at all times.

246 Operation
Driving instructions
Warning!G

Driving when your engine is overheated
can cause some fluids, which may have
leaked into the engine compartment, to
catch fire. You could be seriously
burned.

Steam from an overheated engine can
cause serious burns which can occur
just by opening the hood. Stay away
from the engine if you see or hear steam
coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.

247 Operation
At the gas station
At the gas station
Refueling
The fuel filler flap is located on the
right-hand side of the vehicle towards the
rear. Locking/unlocking the vehicle with
the SmartKey automatically locks/unlocks
the fuel filler flap.
Remove the SmartKey from the starter
switch.
Open the fuel filler flap by pushing at
the point indicated by arrow.
The fuel filler flap opens.
Turn fuel cap counterclockwise and
hold on to it until possible pressure is
released.
Take off cap and set it in the recess on
the fuel filler flap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.
Only fill your tank until the filler nozzle
unit cuts out – do not top off or
overfill.
Replace fuel cap by turning it clockwise
until it audibly engages.
Warning!G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flame or smoking
materials near gasoline!
Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and skin contact, extinguish
all smoking materials.
Direct skin contact with fuels and the inha-
lation of fuel vapors can damage your
health.
iIn case that the central locking system does
not release the fuel filler flap, or the opening
mechanism is clamping, notify Roadside Assis-
tance or an authorized Mercedes-Benz Center.
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average
of 96 RON/86 MON). Information on gasoline
quality can normally be found on the fuel pump.
Warning!G
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gas to
spray back out when removing the fuel
pump nozzle, which could cause personal
injury.