Airbag system113
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
Any work on the side airbag system including removing and installing
system components because of other repair work (e.g. removing seats) must
only be carried out by a specialist garage.
Deactivating an airbagDeactivating airbags
If any airbags have been deactivated, switch them on again as soon as
possible so that they are able to again provide their proper protection.There is the technical means installed within your vehicle to switch off the front or
side* airbag using a diagnostic equipment (take out of commission).
This is why you should have the deactivation of the airbags carried out by a specialist
garage.
On vehicles equipped with the switch for de activation of the airbags, you can deacti-
vate the front passenger airbag and/or side airbag by means of this switch page 113.
Deactivation of airbags is envisaged only for particular instances, such as if:
You must in exceptional cases use a child seat on the front passenger seat where
the child is seated with its ba ck to the direction of travel (in some countries this must
be in the direction of travel due to other legal regulations applying) page 115,
“Important safety information regarding the use of child safety seats”;
you are not able to maintain the distan ce of at least 25 cm between middle of
steering wheel and chest, despite the driver seat being correctly adjusted;
special attachments are required in the ar ea of the steering wheel because of a
physical disability;
you have installed other seats (e.g. orthopaedic seats without side airbags).
Monitoring the airbag system
The functionality of the airbag system is also monitored electronically when one airbag
has been switched off.
If the airbag was switched off using diagnostic equipment:
The airbag indicator light in the instrume nt cluster lights up for about 3 seconds
after switching on the ignition and then flashes after that for about 12 seconds.
The following situation applies if the ai rbag has been switched off using the
switch for the airbag* in the storage compartment:
the airbag indicator light in the instrume nt cluster comes on for about 4 seconds
each time the igniti on is switched on;
The deactivation of the airbag is indicated by the lighting up of the indicator light
at the front interior lighting of the vehicle page 113.
Note
A specialist garage will be able to advise you whether national legislation in your
country allows airbags in your vehicl e to be deactivated, and which ones.Switch for the front passenger airbag(s)*
WARNING (continued)
Fig. 123 Storage compartment:
Switch for the front passenger
airbag(s)
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Airbag system
114
The front passenger airbag as well as side airbag (if the vehicle is fitted with side
airbags) are switched off using the switch. Deactivating an airbag– Switch off the ignition.
– Turn the slot of the airbag switch using the key in the position OFF page 113,
fig. 123 - (vertical position).
– Check whether the indicator light
lights up in the lighting of the interior
of the vehicle (front) when the ignition is switched on page 114, fig. 124 .
Switching on an airbag– Switch off the ignition.
– Turn the slot of the airbag switch using the key in the position ON page 113,
fig. 123 - (horizontal position).
– Check whether the indicator light
does not light up in the lighting of the
interior of the vehicle (front) when the ignition is switched on page 114, fig. 124 .
The airbag should only be switched off under exceptional circumstances page 113.
Indicator light
(airbag switched off)
The indicator light is located at the front interior lighting of the vehicle page 114,
fig. 124 . In cases where the front passenger airbag and also possibly the side airbag* are
switched off
, the indicator light comes on about 4 seconds after the ignition is
switched on.
There is a system fault present in the airbag switch off if the indicator light
flashes. Please have the car inspected i mmediately by a specialist garage.
WARNING
The driver is responsible for whether th e airbag is switched on or switched
off.
Only switch off the airbag when the ignition is switched off! Otherwise a
fault can occur in the system for the airbag deactivation.
If the warning light
(airbag switched off) flashes:
There is a risk of the front passenger airbag not being activated in the
event of an accident. Therefore do not use any child safety seats on the front
passenger seat.
If the front passenger seat is occupied, there is a risk that the airbag is
deployed unexpectedly and thus the occupant of this seat may suffer
possible injuries.
It is also important to have the system inspected without delay by a
specialist garage.
Fig. 124 Indicator light for a
switched off front seat passenger
airbag
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Intelligent Technology123
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
Driving TipsIntelligent TechnologyElectronic stability programme (ESP)*GeneralGeneral
The ESP aids you in maintaining control of your vehicle in situations in which the
vehicle is driving at its dynamic limits, such as entering a curve fast. The risk of skidding
is reduced and your vehicle thus offers greater driving stability depending on the
conditions of the road surface. The system operates at all speeds.
The following systems are integrated into the electronic stability programme:
Electronic Differential Lock (EDL),
Traction control system (TCS),
Antilock brake system (ABS),
Brake Assist.
Operating principle
The ESP switches on automatically when the engine is started and then conducts a self-
test. The ESP control unit processes data from the individual systems. It also processes additional measurement data which are supplied by highly sensitive sensors: the rota-
tional velocity of the vehicle about its vert
ical axis, the lateral acceleration of the
vehicle, the braking pressure and the steering angle.
The direction which the driver wishes to take is determined based on the steering
angle and the speed of the vehicle and is co nstantly compared with the actual behav-
iour of the vehicle. If differences exist, such as the vehi cle beginning to skid, the ESP will
automatically brake the appropriate wheel.
The car is stabilised again by the forces wh ich take effect when the wheel is braked.
Intervention into the brake system takes place primarily on the outer front wheel of a
vehicle which tends to oversteer (tendency for the rear of the vehicle to break away)
while occurs this is on the inner rear wh eel of a vehicle which tends to understeer
(tendency to shift out of the curve). This braking control cycle is accompanied by
noises.
The ESP operates in combination with the ABS page 126, “Antilock brake system
(ABS)*”. If there is a fault in the ABS system, the ESP also does not operate.
The ESP warning light lights up in the instrument cluster when there is a fault on the
ESP page 31.
Switching off
You can switch the ESP off and on agai n as you wish, by pressing the button fig. 134 .
The ESP warning light lights up in the instrument cluster when the system is switched
off page 31.
The ESP should normally always be switched on. It may be good practice in certain
exceptional cases, such as when you wish to have wheel slip, to switch off the system.
Examples:
when driving with snow chains
when driving in deep snow or on a loose surface
when it is necessary to rock a vehicle when it has become stuck.
then you should switch on the ESP again.
Fig. 134 ESP switch
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Intelligent Technology
124WARNING
It is also not possible for the ESP to overcome the physical limits of the vehicle.
Even if a vehicle fitted with ESP you should still always adapt your style of
driving to the condition of the road surface and the traffic situation. This partic-
ularly applies when driving on slippery and wet roads. The increased safety
offered must not tempt you to take greater risks than otherwise - risk of an acci-
dent!
Note
All four wheels must be fitted with the same tyres in order to achieve problem-free
operation of the ESP. Differing rolling circum ferences of the tyres can lead to an unde-
sirable reduction in the engine output.
Changes to vehicle (e.g. on engine, on th e brakes, on chassis or another combina-
tion of tyres and wheels) can influence the function of the ESP page 166, “Accesso-
ries, changes and replacement of parts”.
Electronic Differential Lock (EDL)*
The electronic differential lock prev ents an individual wheel from slip-
ping.Vehicles fitted with ABS* can be equipped with electronic differential lock (EDL).
General
The EDL makes it much easier, and sometimes at all possible, to start off, accelerate
and climb a steep hill when the conditions of the road surface are unfavourable.
Operating principle
The EDL is activated automaticall y, that is without any action on the part of the driver.
It monitors the speeds of the driven wheels with the aid of the ABS sensors. Should
only one drive wheel begin spinning on a slippery surface there will be an appreciable
difference in the speed of the driven wheels. The EDL function brakes the slipping
wheel and the differential transmits a greate r driving force to the other driven wheel.
This control process is also accompanied by noises. Overheating of the brakes
The EDL switches off automatica
lly if unusually severe stresses exist in order to avoid
excessive heat generation in the disc brak e on the wheel which is being braked. The
vehicle can continue to be driven and has the same characteristics as a vehicle not
fitted with EDL.
The EDL switches on again automatically as soon as the brake has cooled down.
WARNING
Carefully depress the accelerator when accelerating on uniformly slippery
road surfaces, such as ice and snow. Th e driven wheels might still spin despite
the EDL and affect the stability of the vehicle - risk of an accident!
You should always adapt your style of driving to the condition of road
surface and to the traffic situation even when your vehicle is fitted with EDL.
The increased safety offered must not tempt you to take greater risks than
otherwise - risk of an accident!Note
If the ABS warning light comes on, this may also indicate a fault in the EDL. Please
have the vehicle inspected as soon as possible by a specialist garage.
Changes to vehicle (e.g. on engine, on the brakes, on chassis or another combina-
tion of tyres and wheels) can influence the function of the EDL page 166, “Accesso-
ries, changes and replacement of parts”.
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Intelligent Technology125
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
Traction control system (TCS)
The traction control system prevents the driven wheels from spinning
when accelerating.General
The TCS makes it much easier, and sometimes at all possible, to start off, accelerate
and climb a steep hill when the conditions of the road surface are unfavourable.
Operating principle
The TCS switches on automatically when th e engine is started and then conducts a
self-test. The system monitors the speeds of the driven wheels with the aid of the ABS
sensors. If the wheels are spinning, the force transmitted to the road surface is auto-
matically adapted by reducing the engine speed. The system operates at all speeds.
The TCS operates in combination with the ABS page 126, “Antilock brake system
(ABS)*”. The TCS will not function if a fault exists in the ABS system.
The TCS warning light lights up in the instru ment cluster when there is a fault on the
TCS page 31.
Switching off
You can switch the TCS off and on again as you wish by pressing the button fig. 135 .
The TCS warning light lights up in the instru ment cluster when the system is switched
off page 31.
The TCS should normally always be switched on. It may be good practice in certain
exceptional cases, such as when you wish to have wheel slip, to switch off the system. Examples:
when driving with snow chains
when driving in deep snow or on a loose surface
when it is necessary to rock a vehicle when it has become stuck.
then you should switch on the TCS again.
WARNING
You should always adjust your style of driving to the conditions of the road
surface and the traffic situation. The increased safety offered must not tempt
you to take greater risks than otherwise - risk of an accident!
Note
All four wheels must be fitted with the same tyres in order to achieve problem-free
operation of the TCS. Differing rolling circumferences of the tyres can lead to an unde-
sirable reduction in the engine output.
Changes to vehicle (e.g. on engine, on the brakes, on chassis or another combina-
tion of tyres and wheels) can influence the function of the TCS page 166, “Accesso-
ries, changes and replacement of parts”.
BrakesWhat has a negative effect on braking efficiency?Wear-and-tear
Wear-and-tear to the brake pa ds is greatly dependent on the operating conditions of
the vehicle and your style of driving. Particularly if you drive a great deal in towns and
over short distances or if you adopt a sporty style of driving, it may be necessary to
have the thickness of the brake pads insp ected at a specialist garage between the
service inspections.
Wet roads or road salt
There may be a certain delay before the brakes take full effect un der certain conditions
such as when driving through water, during heavy rain showers or after the vehicle has
been washed in an automatic vehicle wash , since the brake discs and brake pads may
Fig. 135 TCS switch
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Intelligent Technology
126
be moist or even have a coatin g of ice on them in winter. Yo u s h o u l d d r y t h e b r a k e s a s
soon as possible by applying and releasing the brakes several times.
There also may be a certain delay before the full braking efficiency is available when
driving on roads which have been treated wi th road salt if you have not used the
brake s for s ome cons ide ra bl e time be foreha nd . T he la yer of s alt on the brake di scs a nd
brake pads must first be rubbed off when you apply the brakes.
Corrosion
Corrosion on the brake discs and dirt on th e bake pads occur if the vehicle has been
parked for a long period an d if you do not make much use of the braking system.
We recommend cleaning the brak e discs by firmly applying the brakes at a fairly high
speed if you do not make much use of the braking system or if surface corrosion is
present .
Faults in the brake surface
If you notice that the braking distance ha s suddenly become longer and that the brake
pedal can be depressed further, it is possible that a brake circuit of the dual-circuit
brake system has failed. Drive, in such cases, to the nearest specialist garage without
delay in order to have the problem rectified. Drive at a reduced speed while on your
way to the dealer and adapt your style of driving to the higher brake pedal pressure
required.
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, compensate for this slightly reduced br
aking force by increasing the pressure
on the brake pedal. This guideline also applies to any new brake pads installed
at a future date.
Caution
Never allow the brakes to rub by applying slight pressure if you do not wish to
brake the vehicle. This causes the brakes to overheat and can also result in a longer
braking distance and excessive wear.
Before negotiating a steep downhill section, reduce your speed, shift down into the
next lower gear. This enables you to make full use of the braking power of the vehicle
and reduces the strain on the brakes. Any additional braking should be done intermit-
tently, not continuously.
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.
WARNING (continued)
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Intelligent Technology127
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
You must not expect, however, that the br
aking 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 driving slowly and cautiously, will be longer.
Operating principle
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!
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 30.
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 166, “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 a pply the brakes in good time in dangerous situations, but
do not depress the brake pedal with suffi cient 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 qu ick 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 relatively 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 dece leration of the vehicle. You must apply the brake pedal
firmly and hold it in this position in or der 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.
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
situation.
The increased safety offered by the Brake Assist must not tempt you to take
a greater safety risk than otherwise.
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Towing a trailer135
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
Headlights
Before starting off with a hitched trailer, also check the setting of the headlights. Alter
the setting as necessary with the ai
d of the headlight beam adjuster page 48.
Detachable ball head
The ball rod is detachable on vehicles which feature a factory-fitted towing device. It is
stowed together with separate fitting instructions in the spare wheel well in the
luggage compartment of the vehicle.
Further information on the towing device page 136.
Note
We recommend that you also have your vehicle inspected between service inter-
vals if you tow a trailer frequently.
The handbrake on the towing vehicle must be put on when coupling and decou-
pling the trailer.
Driving Tips
Particular caution is required when towing a trailer.– Do not, as far as possible, drive with your vehicle unladen and the trailer laden.
– Do not make full use of the legal maximum speeds. This applies in particular to downhill sections.
– Apply the brakes in good time.
– Keep a check on the coolant temperature gauge if the outside temperature is high.
Distribution of weight
The distribution of the weight is very poor if your vehicle is unladen and the trailer is
laden. Maintain a particularly low speed if you cannot avoid driving with this combina-
tion.
Driving speed
Do not drive faster than 80 km/hour for safety reasons. This also applies for countries
in which higher speeds are allowed. The fact that the driving stability of the vehicle + trailer combination reduces with
increasing speed means that the legally allowed speed should not be used when there
are unfavourable road, weather or wind cond
itions, particularly near accident black
spots.
You must always reduce your speed immediat ely as soon as you detect even just the
slightest swaying of the trailer. On no account attempt to stop the trailer from
“swaying” by accelerating.
Apply the brakes in good time! If the trailer is fitted with a trailer brake, apply the
brakes gently at first and then brake firmly. This will avoid brake jolts resulting from the
trailer wheels locking. Shift down gears in good time before negotiating a downhill
section to allow the engine to also act as a brake.
Engine overheating
Please keep a check on the coolant temperature gauge if you have to negotiate a
lengthy slope in a low gear at a high engi ne speed when the outside temperature is
very high page 16.
If the needle of the coolant temperature gauge moves into the right-hand area or even
the red area of the scale, reduce your speed immediately. Stop and switch off the
engine if the warning light
in the instrument cluster begins flashing. Wait a few
minutes and check the level of coolant in the coolant expansion bottle page 153,
“Inspecting the coolant level”.
Please refer to the following guidelines page 28, “Coolant temperature/coolant
level ”.
The coolant temperature can be reduced by switching on the heating.
Any increase in the cooling effect of the coolant fan through shifting down a gear and
increasing the engine speed is not possible since the fan speed is independent of the
engine speed. One should also not drop a gear for this reason when towing a trailer as
long as the engine can manage th e slope without any drop in speed.
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