Page 137 of 231

Intelligent Technology
136
Low brake fluid level
An insufficient level of brake fluid may result in problems in the brake system. The level
of the brake fluid is monitored electronically page 31, “Brake system ”.
WARNING
Only apply the brakes for the purpose of drying and cleaning the brake discs
if the traffic conditions permit this. Do not place any other road users in jeop-
ardy.
When retrospectively mounting a front spoiler, solid wheel hubs etc. one
must ensure that the air supply to the front wheel brakes is not reduced other-
wise the braking system could run too hot.
Allow for the fact that new brake pads do not achieve their full braking effi-
ciency until approximately 200 kilometres. New brake pads must be first “run
in” before they develop their optimal friction force. You can, however, compen-
sate for this slightly reduced braking force by increasing the pressure on the
brake pedal. This guideline also applie s to any new brake pads installed at a
future date.Caution
Never allow the brakes to rub by applying sl ight pressure if you do not wish to brake
the vehicle. This causes the br akes to overheat and can also result in a longer braking
distance and excessive wear.
Before negotiating a steep downhill sectio n, please reduce your speed and shift
down into the next lower gear (manual gear box) or select a lower driving stage (auto-
matic gearbox). This enables you to make full use of the braking power of the vehicle
and reduces the strain on the brakes. Any ad ditional braking should be done intermit-
tently, not continuously.Note
The brake light flashes automatically in case of an emergency braking at speeds greater
than 60 km/h or with the intervention of th e ABS, which lasts longer than 1.5 seconds.
After the speed was reduced below 10 km/h or the vehicle was stopped, the brake light
stops flashing and the hazard warning light system switches on. The hazard warning
light system is switched off automatically after accelerating or driving off again.
Brake boosterThe brake booster boosts the pressure whic h you generate with the brake pedal. The
necessary pressure is only genera ted when the engine is running.
WARNING
Never switch off the engine befo re the vehicle is stationary.
The brake booster only operates when the engine is running. Greater phys-
ical effort for braking is required when en gine is switched off. Because if you do
not stop as normal, this can cause an accident and severe injuries.
Antilock brake system (ABS)ABS prevents the wheels locking when braking.General
The ABS contributes significan tly to enhancing the active safety of your vehicle.
Compared to a vehicle not fitted with the ABS brake system, you are able to retain
optimal steering ability even during a full br ake application on a slippery road surface
because the wheels do not lock up.
You must not expect, however, that the braking distance will be shorter under all
circumstances as a result of the ABS. The braking distance for example on gravel and
fresh snow, when you should anyway be driv ing slowly and cautiously, will be longer.
Operating principle
As soon as the vehicle speed has increased to about 20 km/hour an automatic test
procedure is conducted during which you will be able to hear a pumping noise for
about 1 second.
The brake pressure will be reduced on a wheel which is rotating at a speed which is too
low for the speed of the vehicle and tending to lock. This control cycle is noticeable
from a pulsating movement of the brake pedal which is accompanied by noises.
This is consciously intended to provide the driver with the information that the wheels
are tending to lock (ABS control range). You must always keep the brake pedal
depressed to enable the ABS to optimally control the brake application in this braking
range. Never interrupt the application of the brakes!
s16g.4.book Page 136 Wednesda y, February 10, 2010 3:53 PM
Page 138 of 231

Intelligent Technology137
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Praktik
Technical Data
WARNING
The ABS can also not overcome the physical limits of your vehicle. Please do
not forget this, particularly when driving on icy or wet road surfaces. If the ABS
is operating within the control range, adapt your speed immediately to the
conditions of the road surface and the traffic situation. The increased safety
offered by the ABS must not tempt you to take greater risks than otherwise -
risk of an accident!
The normal braking system is still fully functional if there is an ABS fault.
Visit a specialist garage as quickly as poss ible and adjust your style of driving to
take account of the ABS fault in the meantime since you will not know the extent
of the fault and in how far the braking efficiency is affected.Note
A warning light comes on if a fault occurs in the ABS system
page 31.
Changes to vehicle (e.g. on engine, on th e brakes, on chassis or another combina-
tion of tyres and wheels) can in fluence the function of the ABS page 179, “Accesso-
ries, changes and replacement of parts”.
Brake Assist*During a severe brake application (e.g. if a hazard exists), the Brake Assist increases the
braking force and thus makes it possible to rapidly produce the pressure required in
the brake system.
The majority of drivers do apply the brakes in good time in dangerous situations, but
do not depress the brake pedal with sufficient pressure. Consequently, it is not possible
for the vehicle to achieve its maximum deceleration and the vehicle covers a greater
distance than necessary.
The Brake Assist is activated by the very quick operation of the brake pedal. In such
cases, a much greater braking pressure exists than during a normal brake application.
This makes it possible, even with a relative ly low resistance of the brake pedal, to
produce an adequate pressure in the brake system in the shortest possible time, which
is required for maximum deceleration of th e vehicle. You must apply the brake pedal
firmly and hold it in this position in order to achieve the shortest possible braking
distance. The Brake Assist is able to help you achi
eve a shorter braking distance in emergency
situations by rapidly producing the pressure required in the brake system. It fully
exploits the attributes of the ABS. After you release the brake pedal, the function of the
Brake Assist is automatically switched off and the brakes operate in the normal way.
The Brake Assist is part of the ESP system. If a fault occurs in the ESP, the Brake Assist
function is also not available. Further information on the ESP page 133.
WARNING
The Brake Assist is also not able to overcome the physical limits of your
vehicle in terms of the braking distance required.
Adapt your speed to the conditions of the road surface and to the traffic situ-
ation.
The increased safety offered by the Brake Assist must not tempt you to take
a greater safety risk than otherwise.
Uphill Start Assist*The uphill start assist makes it easier to start off on steep hills. The system assists a start
off by holding the brake pressure produced by the brake pedal actuation for approx. 2
seconds after releasing the brake pedal. The driver can therefore move his foot from
the brake pedal to the accelerator pedal and start off on the slope, without having to
actuate the handbrake. The brake pressure drops gradually the more you operate the
accelerator pedal. If the vehicle does not start off within 2 seconds, it starts to roll back.
The uphill start assist is active as of a 3% slope, if the driver door is closed. It is always
active on slopes when in forward or reverse start off. When driving downhill, it is
inactive.Electrohydraulic power steeringThe power steering enables you to steer the vehicle with less physical force.
The steering characteristics can be changed by a specialist garage.
s16g.4.book Page 137 Wednesda y, February 10, 2010 3:53 PM
Page 139 of 231

Intelligent Technology
138
You will place great stresses on the power steering system if the steering is turned to
full lock when the vehicle is stationary. Turn ing the steering to full lock in such a situa-
tion will be accompanied by noises.
It is still possible to fully steer the vehicle if the power steering fails or if the engine is
not running (vehicle being towed in). The only difference is that greater physical effort
is required.
It is possible that the hydraulic pump of the power steering will not run due to the low
vehicle network voltage if the battery has gone flat and the engine must started with
the help off jump leads. This condition will be indicated by lighting up of the warning
light.
The power steering operates again if the ba ttery is charged to a specific range when
engine is running. It also op erates again, if the engine can be started with its own
battery.
If there is a fault in the power steering, the warning light lights up in the instrument
cluster
page 25.
Caution
Do not leave the steering at full lock fo r more than 15 seconds when the engine is
running - risk of damaging the power steering!
Note
Have the steering inspected as soon as possible by a specialist garage if there is a leak
or fault in the system.
Tyre pressure monitoring system*The tyre pressure monitoring system compares with the aid of the ABS sensors the
speed and also the rolling circumference of the individual wheels. If the tyre inflation
pressure is significantly changed and thus the rolling circumference of a wheel, the
warning light
lights up in the instrument cluster page 30. The tyre pressure moni-
toring system functions late or too sensitively if:
the structure of the tyre is damaged,
the vehicle is loaded to one side or with a load on the roof,
the wheels of an axle are loaded heavily (e.g. when towing a trailer or when driving
uphill or downhill),
the vehicle is operated in unfavourable wi nter conditions or on an unfirm ground,
snow chains or emergency wheel are mounted,
the driver has a sporty style of driving (with sharp acceleration and high speed
when cornering).
Basic setting of the system
After changing the tyre inflation pressures or after changing one or several wheels, a
basic setting of the system mu st be carried out as follows.
Inflate all tyres to the specified inflation pressure page 173.
Switch on the ignition.
Press button
fig. 127 for more than 2 seconds. While pressing the button,
the warning light
lights up. At the same time the basic values are stored, which is
confirmed with an acoustic sound and then the warning light
goes out.
Fig. 127 Button for setting the tyre
inflation pressure control value
s16g.4.book Page 138 Wednesda y, February 10, 2010 3:53 PM
Page 140 of 231

Intelligent Technology139
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Praktik
Technical Data
If the warning light
does not go out after the basic setting, there is a fault in the
system. Have the vehicle inspected by your nearest specialist garage.
Functional description
After the basic setting of the system the “adaptation” of the tyre inflation pressures and
then the tyre pressure control in the individual tyres are performed.
Warning light
lights up
If the tyre inflation pressure of at least one wheel is insufficiently inflated in comparison
to the stored basic value, the warning light
lights up. Inflate all tyres to the
specified inflation pressure page 173, “Tyre life” and then perform a basic setting of
the system.
Warning light
flashes
If the warning light flashes, there is a system fault. Have the vehicle inspected by your
nearest specialist garage.
WARNING
When the warning light
lights up, immediately reduce the speed and
avoid sudden steering and brake manoeuvr es. Please stop the vehicle without
delay at the nearest possible stop and in spect the tyres and their inflation pres-
sures.
The driver is responsible for the correct tyre inflation pressures. For this
reason, the tyre inflation pressu res must be checked regularly.
Under certain circumstances (e.g. sporty style of driving, wintry or unpaved
roads) the warning light
can be delayed or does not light up at all.
The tyre pressure monitoring system does not take away the responsibility
from the driver for the correct tyre inflation pressure.Note
The tyre pressure monitoring system:
does not replace the regular tyre inflatio n pressure control, because the system
cannot detect an even pressure loss;
cannot warn in case of very rapid tyre inflation pressure loss, e.g. in case of sudden
tyre damage. In this case ca refully bring the vehicle to a standstill without sudden
steering movements and without sharp braking.
Diesel particle filter* (diesel engine)In the diesel particle filter the resu lting soot particles are collected and
burnt during the combustion of diesel fuel.Code 7GG, 7MB or 7MG on the vehicle data sticker, see fig. 128 , indicates that your
vehicle is equipped with a diesel particle fi lter. The vehicle data sticker is located on
the floor of the luggage compartment and is also stated in the Service schedule.
The diesel particle filter filters the soot particles completely from the exhaust. The soot
is collected in the diesel particle filter and burnt regularly. To assist this procedure, we
recommend not to drive regu larly over short distances.
If the diesel particle filter is clogged or there is a fault, it is indicated by the warning light
page 32, “Diesel particle filter* (diesel engine)”.
WARNING
The diesel particle filter achieves very high temp eratures. Therefore do not
park at points where the hot filter comes into direct contact with dry grass or
other combustible materials - risk of fire!
Never use additional underbody protection or corrosion-protection agents
for the exhaust pipes, catalytic converters, diesel particle filter or heat shields.
Fig. 128 Vehicle data sticker
s16g.4.book Page 139 Wednesday, February 10, 2010 3:53 PM
Page 141 of 231
Intelligent Technology
140
When the engine reaches its operating temperature, these substances might
ignite - risk of fire!
Note
When using diesel fuel with high sulphur content the life of the diesel particle filter
is clearly reduced. A specialist garage will be able to tell you which countries use only
diesel fuel with high sulphur content.WARNING (continued)
s16g.4.book Page 140 Wednesda y, February 10, 2010 3:53 PM
Page 142 of 231

Driving and the Environment141
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Praktik
Technical Data
Driving and the EnvironmentThe first 1 500 kilometres and then afterwardsA new engine
The engine has to be run in during the first 1 500 kilometres.Up to 1 000 kilometres– Do not drive faster than 3/4 of the maximum speed of the gear in use, that is 3/4 of
the maximum permissi ble engine speed.
– Do not use full throttle.
– Avoid high engine revolutions.
– Do not tow a trailer.From 1 000 up to 1 500 kilometres– Increase the power output of the engine gradually up to the full speed of the gear
engaged, that is up to the maxi mum permissible engine revolutions.
During the first operating hours the engine ha s higher internal friction than later until
all of the moving parts have harmonized. Th e driving style which you adopt during the
first approx.1 500 kilometres plays a decisive part in the success of running in your
vehicle.
You should not drive at unnecessarily high engine revolutions even after the
running-in period is complete . The maximum permissible en gine speed is marked by
the beginning of the red zone on the scale of the revolutions counter. Shift up into the
next higher gear on a vehi cle fitted with manual gear box before the red zone is
reached. During acceleration (depressing the accelerator) exceptionally high engine
speeds are automatically reduced, yet the engine is not protected against too high
engine speeds which are caused by incorrectly shifting down the gears resulting in a
sudden increase of the engine speeds above the permitted maximum revolutions
which can lead to engine damage.
For a vehicle fitted with a manual gearbox the converse situation also applies: Do not
drive at engine revolutions which are too low. Shift down as soon as the engine is no
longer running smoothly.
Caution
All the speed and engine revolution figures ap ply only when the engine is at its normal
operating temperature. Never rev up an engine which is cold, neither when the vehicle
is stationary nor when driving in individual gears.
For the sake of the environment
Not driving at unnecessari ly high engine revolutions and shifting to a higher gear as
early as possible are ways to minimise fuel consumption, operating noise levels as well
as protects the environment and contributes to a longer life and reliability of the
engine.New tyresNew tyres have to be “run in” since they do not offer optimal grip at first. You should
take account of this fact for the first 500 kilometres and drive particularly carefully.New brake padsAllow for the fact that new brake pads do no t achieve their full braking efficiency until
approximately 200 kilometres. New brake pads must be first “run in” before they
develop their optimal friction force. You ca n, however, compensate for this slightly
reduced braking force by increasing the pressure on the brake pedal.
This guideline also applies to any new brake pads installed at a future date.
During the running-in pe riod, you should avoid excessive stresses on the brakes. This
includes, for example, violent braking, part icularly from very high speeds, and also
when crossing mountain passes.
s16g.4.book Page 141 Wednesda y, February 10, 2010 3:53 PM
Page 143 of 231

Driving and the Environment
142
Catalytic converterProper operation of the emission cont rol system (catalytic converter) is
of major significance for driving your vehicle in an environmentally
conscious way.Please refer to the following guidelines:
– For vehicles with petrol engine only refuel with unleaded petrol page 158,
“Grades of petrol”.
– Never run the fuel tank completely empty.
– Do not switch off the ignition while you are driving the vehicle.
– Do not pour too much oil into the engine page 164, “Replenishing engine oil”.
– Do not tow-start the vehicle over a distance of more than 50 metres page 189,
“Tow-starting a vehicle”.
If you drive your vehicle in a country in which unleaded petrol is not available, you
must have the catalytic converter replaced la ter when driving the vehicle into a country
in which use of a catalyti c converter is mandatory.
WARNING
In view of the high temperatures which may be produced in the catalytic
converter, one should always park a vehicle in such a way that the catalytic
converter cannot come into contact with easily flammable materials below the
vehicle - a risk of fire!
Never use additional underbody protection or corrosion-protection agents
for the exhaust pipes, catalytic converters or heat shields. Such substances
might ignite when driving - risk of fire!Caution
On vehicles fitted with a catalytic converte r, never let the fuel tank run completely
empty. An irregular fuel supply can result in poor ignition or misfiring. Unburnt fuel
may get into the exhaust system and damage the cata lytic converter.
Filling the tank even only once with leaded petrol will result in the catalytic
converter being destroyed.
If you detect misfir ing, a drop in performance or irregular engine running when
driving, reduce your speed immediately and have the vehicle inspected by the nearest
specialist garage. The symptoms described ma y be caused by a fault in the ignition
system. Unburnt fuel may get into the exhaust system and damage the catalytic
converter.For the sake of the environment
Even if the exhaust system is operating pr operly, a sulphur-like exhaust odour may be
produced under certain oper ating conditions of the engine. This depends on the
sulphur content of the fuel. It is often sufficient to refuel with unleaded premium-grade
petrol of a different brand or at a different filling station.Driving in an economical and environmentally
conscious mannerGeneral
Your personal style of driving is a major factor.Your fuel consumption, any pollution of the environmental and the wear-and-tear to
the engine, brakes and tyres, depend essentially on three factors:
your personal style of driving;
the conditions under which your vehicle is operated;
technical aspects.
You can easily improve your fuel economy by 10 - 15 percent by driving in an econom-
ical way with foresight. This section is intended to provide you with a number of tips on
how to protect the environment and at the same time save money.
The fuel consumption can naturally also be influenced by factors which are beyond the
driver's control. It is, for example, normal for the fuel consumption to increase in
winter and under worsened cond itions such as poor road conditions, towing a trailer,
etc.
The technical requirements for low fuel usage and economic efficiency of the vehicle
have already been built into the vehicle at the works. Special attention has been given
to minimising negative effects on the environment. It is necessary to take note of the
s16g.4.book Page 142 Wednesda y, February 10, 2010 3:53 PM
Page 144 of 231

Driving and the Environment143
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Praktik
Technical Data
guidelines given in this chapter in order to
make best use of these characteristics and
to maintain their effectiveness.
Looking ahead when driving
A vehicle's highest fuel consumption occurs it accelerates.Avoid accelerating and braking unnecessarily. If you drive with forsight you will not
need to brake so often and will also then not have to accelerate so much. Let your
vehicle coast to a stop, for example, if this is possible, when you see that the next set of
traffic lights is at red.Shifting gears and saving energy
Shifting up early saves on fuel.Fig. 129 Fuel consumption / Shift recommendation for changing gearsManual gearbox– Drive no more than about one length of your vehicle in first gear.
– Shift up into the next higher gear at approx. 2 000 to 2 500 revs.Automatic gearbox– Depress the accelerator pedal slowly. Do not depress it beyond the kickdown
position, however.
An effective way of achieving good fuel economy is to shift up early. You will consume
more fuel if you drive at unnecessaril y high revolutions in any given gear. The
fig. 129 shows the ratio of fuel consumption to the speed of your vehicle in the
relevant gear. Fuel consumption in 1st gear is the highest. The consumption is the
lowest in the highest gear.
You will achieve good fuel economy by shif ting up early and shifting down late.
Shift recommendation for changing gears*
An information for the engaged gear fig. 129 is shown in the display of the
instrument cluster.
In order to minimise the fuel consumptio n, a recommendation for shifting into
another gear is indicated in the display.
If the control unit recognises that it is appropriate to change the gear, an arrow is
shown in the display. The arrow points up or down, depending on whether it is recom-
mended to shift into a higher or lower gear.
At the same time, the recommended gear is indicated instead of the currently engaged
gear .
Note
Also use the information supplied by the multi-functional indicator* page 18.Avoiding full throttle
Driving more slowly means saving fuel.Sensitive use of the accelerator will not only significantly reduce fuel consumption but
also positively influence environmenta l pollution and wear of your vehicle.
AA
AB
AA
Fig. 130 Fuel consumption in litres/100
km. and speed in km/h.
s16g.4.book Page 143 Wednesday, February 10, 2010 3:53 PM