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”.
s2rc.book Page 124 Thursday, April 22, 2010 10:58 AM
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)
s2rc.book Page 126 Thursday, April 22, 2010 10:58 AM
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.
s2rc.book Page 135 Thursday, April 22, 2010 10:58 AM
Fuel
146
– Unscrew the fuel filler cap anti-clockwise and place the fuel filler cap from above
on the fuel filler flap page 145, fig. 141 .Closing fuel filler cap– Screw on the cap by turning it to the right until it is heard to lock.
– On vehicles without remote unlocking of the fuel filler flap from the driver's seat,
lock the fuel filler cap on the fuel filler tube by turning the vehicle key to the right
and withdraw the key.
– Close the fuel filler flap until it locks.Open the fuel filler flap from the driver's seat*– Press the switch to open the fuel filler flap page 145, fig. 140 .
– Unscrew the fuel filler cap anti-clockwise and place the fuel filler cap from above
on the fuel filler flap page 145, fig. 141 .Closing fuel filler cap– Screw on the cap by turning it to the right until it is heard to lock.
– Close the fuel filler flap until it locks.
The correct grade of fuel for your vehicle as well as the tyre size and inflation pressures
are stated on a sticker affixed to the inside of the fuel filler flap. Further information on
fuel page 144, “Fuel”.
The fuel tank has a capa city of about 55 litres.
WARNING
Pay attention to any legal requirements if you do carry a spare canister in the
vehicle. We do not recommend carrying any fuel canisters in your vehicle for
safety reasons. The canister can be da maged in the event of an accident and
fuel may leak out.
Caution
Before refuelling it is necessary to switch off the auxiliary heating system (auxiliary
heating and ventilation) *.
Remove any fuel which has spilled onto th e paintwork of your vehicle immediately
- risk of paint damage!
On vehicles fitted with a ca talytic converter, never let th e fuel tank run completely
empty. An irregular supply of fuel to the engine can result in misfiring and unburnt fuel
may get into the exhaust system, which may result in overheating and damage to the
catalytic converter.
Make sure that the valve is not pressed into the filler tube when inserting the pump
nozzle into the filler tube. Otherwise you are unintentionally filling up the volume,
which in case of heat can caus e an expansion of the fuel. This can lead to an overflow
of fuel or damage to parts of the fuel reservoir.
The fuel tank is full just as soon as the pump nozzle switches off for the first time,
provided the nozzle has been operated properly. Do not continue refuelling - other-
wise the expansion volume is filled up.
s2rc.book Page 146 Thursday, April 22, 2010 10:58 AM
Inspecting and replenishing153
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
Caution
Other coolant additives may cause operational problems which, in partic-
ular, involves significantly reducing the anticorrosion effect.
Any faults or problems resulting from corrosion may cause a loss of coolant
and, as a consequence of this, result in major engine damage.
Inspecting the coolant levelThe coolant expansion bottle is located in the engine compartment on the right.
– Switch the engine off.
– Open the bonnet in “Working in the engine compartment” on page 148.
– Check the level of coolant in the coolant expansion bottle fig. 148 . When the
engine is cold, the coolant level must lie between the and markings. When
the engine is warm, the level may also lie slightly above the hatched part.
If the coolant level in the reservoir is too lo w, this is indicated by the warning light in
the instrument cluster
page 28. We nevertheless recommend inspecting the
coolant level directly at the reservoir from time to time.
Loss of coolant
A loss of coolant is first and foremost an indication of a leak in the system. You should
not merely top up the coolant in the reservoir. It is also important to have the cooling
system inspected without delay by a specialist garage. Losses can only occur through the pressure
relief in the cap of the coolant expansion
bottle which is completely free of leaks if the coolant boils as a result of overheating
and is forced out of the cooling system.
WARNING
Read and observe the warning notes page 148, “Working in the engine
compartment” before working in the engine compartment.
Caution
One should contact a specialist garage as s oon as possible if the source of overheating
itself cannot be determined and removed, since there may be grave damage to the
engine.Replenishing the coolant– Switch the engine off.
– Allow the engine to cool down.
– Place a cloth over the cap of the coolant expansion reservoir fig. 148 and
unscrew the cap carefully by turning it to the left .
–Top up the coolant.
– Screw the cap tight until it is heard to lock.
The coolant which you use for replenishing th e system, must comply with one specific
specification page 152, “Coolant”. Do not use an al ternative additive if the coolant
additive G13 is not available in exceptional cases. Just top up the system with water
and as soon as possible arrange adjustment to correct the mixing ratio of water and
coolant additive again by a specialist garage.
Only use fresh coolant for topping up the system.
Do not top up the fluid above the hatched pa rt! Excess coolant which is heated up is
forced out of the cooling system through th e pressure relief valve in the cap of the
coolant compensation bottle.
Wait until the engine has cooled down for a system which has suffered a major loss of
coolant before pouring in coolant. This is necessary to avoid engine damage.
Fig. 148 Engine compartment:
Coolant expansion bottleAa
Ab
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