2012 MERCEDES-BENZ SL ROADSTER overheating

in the ECO display does not indicate a fixed
consumption.
In addition to driving style, the consumption is
affected by many other factors, such as:
R load
R tyre pressure
R cold start
R choice of route
R the use of electrical consumers
These factors are not included in the ECO dis-
play.
The evaluation of your driving style takes the following three categories into consideration:
R Acceleration
Acceleration (evaluation of all accelera-
tion processes):
- The bar fills up: moderate acceleration,
especially at higher speeds
- The bar empties: sporty acceleration
R Constant Constant (assessment of driving behav-
iour at all times):
- The bar fills up: constant speed and
avoidance of unnecessary acceleration
and deceleration
- The bar empties: fluctuations in speed
R Coasting
Coasting (assessment of all deceleration
processes):
- The bar fills up: anticipatory driving,
keeping your distance and early release
of the accelerator. The vehicle can coast
without use of the brakes
- The bar empties: frequent braking
i An economical driving style involves driv-
ing at a moderate engine speed.
To achieve a higher value in the categories
Acceleration
Acceleration andConstant Constant :
R observe the gearshift recommendation.
R drive the vehicle in drive program E.
i On long journeys at a constant speed, e.g.
on the motorway, only the bar for Constant
Constant
will change.
i The ECO display summarises the driving
characteristics from the start of the journey to its completion. Therefore, there are
dynamic changes in the bars at the start of
a journey. During a prolonged driving time, these changes are smaller. For more
dynamic changes, perform a manual reset.
For further information on the ECO display,
see (Y page 232). Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients Change into a lower gear in good time on long
and steep downhill gradients. Take particular note of this when driving a laden vehicle.
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC.
This will use the braking effect of the engine,
so less braking will be required to maintain
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving. Driving tips
179Driving and parking Z

You should pay special attention to road con-
ditions when temperatures are around the
freezing point.
For more information on driving with snow
chains, see (Y page 599).
For more information on driving with summer tyres, see (Y page 598).
Observe the notes in the "Winter operation"
section (Y page 598). Driving systems
Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must select a lower gear in good time. By doing so, you will make use of
the braking effect of the engine. This relieves the load on the brake system and prevents
the brakes from overheating and wearing tooquickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a
steady speed for a prolonged period. You can store any road speed above 30 km/h.
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of acci-
dent nor override the laws of physics. Cruise
control cannot take road, weather and traffic
conditions into account. Cruise control is only
an aid. You are responsible for the distance to the vehicle in front, for vehicle speed, for
braking in good time and for maintaining lane. Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed, e.g.
heavy traffic or winding roads.
R on slippery roads. Braking or accelerating
may cause the drive wheels to lose traction
and the vehicle could then skid.
R when there is poor visibility, e.g. due to fog,
heavy rain or snow.
If there is a change of drivers, advise the new
driver of the stored speed.
Cruise control lever Cruise control lever
:
To store the current speed or a higher
speed
; LIM indicator lamp
= To store the current speed and to call up
the last stored speed
? To store the current speed or a lower
speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever.
LIM indicator lamp ;on the cruise control
lever indicates which system you have selec- ted:
R LIM indicator lamp ;
; off: cruise control
is selected.
R LIM indicator lamp ; ;on: variable
SPEEDTRONIC is selected. 182
Driving systemsDriving and parking

DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS brakes automatically so that
the set speed is not exceeded.
On long and steep downhill gradients, espe-
cially if the vehicle is laden, you must select a lower gear in good time. By doing so, you will make use of the braking effect of the engine.
This relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
If a slower-moving vehicle is detected in front, DISTRONIC PLUS brakes your vehicle. It
maintains the preset distance to the vehicle infront.
If DISTRONIC PLUS detects that there is a risk
of a collision, you will be warned visually and acoustically. Without your intervention, DIS-
TRONIC PLUS cannot prevent a collision. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
For DISTRONIC PLUS to assist you, the radar
sensor system must be operational.
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control in the speed range between 30 km/h and 200 km/h. If a vehicle is driving in front ofyou, it operates in the speed range between
0 km/h and 200 km/h.
Do not use DISTRONIC PLUS while driving on roads with steep gradients. Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 40% of the maximum braking force. If this
braking force is insufficient, DISTRONIC PLUS
warns you visually and audibly. There is a risk
of an accident.
In such cases, apply the brakes yourself and
try to take evasive action. Driving syste
ms
185Driving an d parking Z

vehicle is laden, you must select a lower gear
in good time. By doing so, you will make use of the braking effect of the engine. This relieves
the load on the brake system and prevents
the brakes from overheating and wearing too quickly.
You can set a variable or permanent limit
speed:
R variable for speed limits, e.g. in built-up
areas
R permanent for long-term speed restric-
tions, e.g. when driving with winter tyres
fitted (Y page 196)
i The speed indicated in the speedometer
may differ slightly from the limit speed
stored.
Important safety notes If you fail to adapt your driving style, SPEED-
TRONIC can neither reduce the risk of acci-
dent nor override the laws of physics. SPEED-
TRONIC cannot take into account road,
weather or traffic conditions. SPEEDTRONIC
is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time, and for staying cor-
rectly in lane.
If there is a change of drivers, advise the new
driver of the speed stored. Variable SPEEDTRONIC Cruise control lever
Cruise control lever
:
To store the current speed or a higher
speed
; LIM indicator lamp
= To store the current speed and to call up
the last stored speed
? To store the current speed or a lower
speed
A To switch between cruise control or DIS-
TRONIC PLUS and variable SPEEDTRONIC
B To deactivate variable SPEEDTRONIC
With the cruise control lever, you can operate
cruise control or DISTRONIC PLUS and vari-
able SPEEDTRONIC.
LIM indicator lamp ;on the cruise control
lever indicates which system you have selec-
ted:
R LIM indicator lamp ;
; off: cruise control
or DISTRONIC PLUS is selected.
R LIM indicator lamp ; ;on: variable
SPEEDTRONIC is selected.
You can use the cruise control lever to limit
the speed to any speed above 30 km/h while the engine is running. 194
Driving systemsDriving and parking

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 34). Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make
sure your vehicle is operating safely at all times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
For an overview, see the instrument panel
illustration (Y
page 40). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior can be adjusted using the brightness con- trol knob.
The brightness control knob is on the bottom
left of the instrument cluster (Y page 40).
X Turn the brightness control knob anti-
clockwise or clockwise.
If the light switch is set to Ã,Tor
L, the brightness is dependant upon
the brightness of the ambient light.
i The light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not lit. Coolant temperature gauge
G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
The coolant temperature gauge is in the
instrument cluster on the right-hand side
(Y page 40).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 120 †. 228
Displays and operationOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions There is overheating due to excessive temperatures in the vehicle
interior.
X Wait until the vehicle interior has cooled down.
X Restart the update. COMAND Online's integrated hard disk is defective.
X Consult a Mercedes-Benz Service Centre. Problem
Possible causes/consequences and
M
MSolutions COMAND Online asks
for an activation code
during the map update. The digital map is secured with an activation code.
X Consult a Mercedes-Benz Service Centre. Telephone
Features of your COMAND Online
This Supplement describes all the standard
and optional equipment for your COMAND
Online system, as available at the time of
going to print. Country-specific differences
are possible. Please note that your
COMAND Online system may not be equip-
ped with all the features described. General notes
Important safety notes G
WARNING
Operating communications equipment inte-
grated into the vehicle while driving will dis-
tract you from traffic conditions. You could
then lose control of the vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi- cle is stationary. G
WARNING
If you use the RF transmitter in the vehicle in
an improper way, its electromagnetic radia-
tion can disrupt vehicle electronics, e.g. if:
R the RF transmitter is not connected to an
exterior aerial
R the exterior aerial is fitted incorrectly or is
not a low-reflection aerial
This can jeopardise the operating safety of the vehicle. There is a risk of an accident.
Have the low-reflection exterior aerial fitted at
a qualified specialist workshop. When oper-
ating in the vehicle, always connect the RF
transmitter to the low-reflection exterior aer-
ial.
You must observe the legal requirements for
the country in which you are currently driving
when operating mobile communications
equipment in the vehicle.
Excessive levels of electromagnetic radiation
may cause damage to your health and to the
health of others.
There is scientific discussion surrounding the possible health risks posed by electromag-
netic fields. You can reduce this risk by using
an exterior aerial. Telephone
387COMAND Online Z

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 34). Engine compartment
Bonnet
Important safety notes G
WARNING
An unlocked bonnet may open while driving
and block your view. There is a risk of an acci- dent.
Never unlock the bonnet while driving. G
WARNING
When being opened and closed, the bonnet
may suddenly fall into the closed position.
There is a risk of injury to persons in the range of movement of the bonnet.
Open and close the bonnet only when nobody
is in the range of movement. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan
R remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts.
Active bonnet (pedestrian protection) Operating principle
! An active bonnet that had been triggered
must be repaired at a qualified specialist
workshop. The active bonnet function will
then be available again. The additional
pedestrian protection provided by the
active bonnet will then be restored.
The active bonnet is only available in certain
countries.
The active bonnet can reduce the risk of injury to pedestrians in certain accident situations.
Raising the active bonnet increases the clear-
ance to hard components, such as the engine.
If the active bonnet has been triggered, it is
raised at the rear in the area around the hinge
by approximately 85 mm. The active bonnet is triggered by pyrotechnics.
For the drive to the workshop, reset the trig-
gered active bonnet yourself. If the active
bonnet has been triggered, pedestrian pro-
tection may be limited.
Resetting G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system. 562
Engine compartmentMaintenance and care

Viscosity describes the flow characteristics
of a fluid. If an engine oil has a high viscosity
rating, it flows slowly; the lower the viscosity,
the faster it flows.
Engine oil selection is based on the respective outside temperatures and in accordance with
the SAE classification (viscosity). The table
shows you which SAE classifications are to be
used. The low-temperature properties of
engine oils can be significantly impaired dur-
ing operation due to, for example, ageing or
soot and fuel accretion. It is therefore
strongly recommended to observe regular oil changes using an approved engine oil with the
appropriate SAE classification. Brake fluid
G
WARNING
The brake fluid continuously absorbs mois-
ture from the air. This results in the boiling
point of the brake fluid lowering. If the boiling
point of the brake fluid is too low, vapour
pockets may form when the brakes are sub-
jected to a heavy load. This would impair brak- ing efficiency. There is a risk of an accident.
Have the brake fluid renewed at the prescri-
bed intervals.
When handling brake fluid, observe the
important safety notes on service products
(Y page 622).
The brake fluid change intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Service
Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you top up
the antifreeze. Make sure that antifreeze is
not spilled next to the filler neck. Thoroughly
clean the antifreeze from components before
starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications for Service Products, MB Specifications for Service Products 310.1, e.g. on the Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Service
Booklet.
Comply with the important safety precautions for service products when handling coolant
(Y page 622).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It is responsible
for the following:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of Service products and capacities
627Technical data Z