Intelligent Technology157
Using the systemSafetyDriving TipsGeneral MaintenanceBreakdown assistanceTechnical Data
The TCS should normally always be switched
on. It may be good practice to switch
the system off only in particular exceptional situations if you desire wheel slip.
Examples:
•when driving with snow chains,
•when driving in deep snow or on a loose surface,
•when it is necessary to rock a car free when it has become stuck.
then you should switch on the TCS again.
The EDL ⇒page 157, “Electronic Differential Lock (EDL)” is a part of the TCS. THE
EDL operates independently of the TCS (a lso when the TCS has been switched off
using the TCS button).
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 rollin g circumferences of the tyres can lead to
an undesirable reduction in the engine output.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other assign-
ment of tyres and wheels) can influence the function of the TCS ⇒page 205,
“Accessories, changes and replacement of parts”.
Electronic Differential Lock (EDL)
The electronic differential lock pr events an individual wheel from
slipping.
General
The EDL makes it much easier, and sometimes at all possible, to start off, accelerate
and climb a steep hill when the conditio ns of the road surface are unfavourable. Operating principle
The EDL is activated automatically, 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 sl ippery 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 greater driving force to the other
driven wheel. This control proce ss is also accompanied by noises.
Overheating of the brakes
The EDL switches off automatically if unus ually severe stresses exist in order to
avoid excessive heat generation in the disc brake 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
•Depress the accelerator carefully when accelerating on uniformly slip-
pery road surfaces, such as ice and sn ow. The 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 car inspec ted as soon as possible by a specialist garage.
•Changes to vehicle (e.g. on engine, on the brakes, on chassis or other assign-
ment of tyres and wheels) can in fluence the function of the EDL ⇒page 205,
“Accessories, changes and replacement of parts”.
NKO B5 20.book Page 157 Friday, March 2, 2007 1:46 PM
Intelligent Technology
158
Brakes
What has a negative effect on braking efficiency?
Wear-and-tear
Wear-and-tear to the brake pads 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 neces-
sary to have the thickness of the brake pads inspected 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 under certain condi-
tions 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 be moist or even have a coating of ice on them in winter. You
should dry the brakes as soon as possib le (by applying and releasing the brakes
several times, if the road conditions and the traffic situation allows it).
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
brakes for some considerable time beforeha nd. The layer of salt on the brake discs
and brake pads must first be rubb ed 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 and if you do not make much use of the braking system.
We recommend cleaning the brake 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 corro-
sion is present ⇒.
Faults in the brake surface
If you notice that the braking distance has 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 29, “Brake system ”.
WARNING
•Only apply the brakes for the purpos e of drying and cleaning the brake
discs if the traffic conditions permit this. Do not place any other road users
in jeopardy.
•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
otherwise the braking sy stem could run too hot.
•Allow for the fact that new brake pads do not achieve their full braking
efficiency until approximately 200 kilo metres. New brake pads must be first
“run in” before they develop their optimal friction force. You can, however,
compensate for this slightly reduced braking force by increasing the pres-
sure on the brake pedal. This guidelin e also applies to any new brake pads
installed at a future date.
Caution
•Never allow the brakes to ru b 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 sect ion, please reduce your speed, shift
down into the next lower gear (manual ge arbox) or select a lower driving stage
(automatic gearbox). 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
intermittently, not continuously.
Brake booster
The brake booster boosts the pressure which you generate with the brake pedal.
The necessary pressure is only gene rated when the engine is running.
NKO B5 20.book Page 158 Friday, March 2, 2007 1:46 PM
Towing a trailer
170
should be attached to folding arms. Adjust the mirrors so that they provide you with
an adequate field of view to the rear.
Headlights
Before starting off with a hitched trailer, also check the setting of the headlights.
Alter the setting as necessary with the aid of the headlight beam adjuster
⇒ page 48.
Detachable ball head
The ball rod is detachable on vehicles wh ich 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 171.
Note
•We recommend that you also have yo ur vehicle inspected between service
intervals if you tow a trailer frequently.
•The handbrake on the towing vehicle must be put on when coupling and
decoupling 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 temper ature gauge if the outside temper-
ature 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
combination.
Driving speed
Do not drive faster than 80 km/h 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 conditions, particularly near accident
black spots.
You must always reduce your speed immedi ately 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 down-
hill 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 12.
If the needle of the coolant temperature gauge moves into the right-hand area or
even the red area of the scale, reduce yo ur speed immediately. Stop and switch off
the engine if the warning light
in the instrument cluste r begins flashing. Wait a
few minutes and check the level of coolant in the coolant expansion bottle
⇒ page 190, “Inspecting the coolant level”.
Please refer to the following guidelines ⇒page 26, “Coolant temperature, Coolant
quantity ”.
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
NKO B5 20.book Page 170 Friday, March 2, 2007 1:46 PM
Fuel183
Using the systemSafetyDriving TipsGeneral MaintenanceBreakdown assistanceTechnical Data
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
•Remove any fuel which has spilled onto the paintwork of your vehicle immedi-
ately - risk of paint damage!
•Vehicles fitted with catalytic converter sh ould never be allowed to let the fuel
tank to 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. Otherwis e you are unintentionally filling up the
volume, which in case of heat can cause an expansion of the fuel. This can lead to
an overflow of fuel or damage to parts of the fuel reservoir.
•T h e f u e l t a n k i s f u l l j u s t a s s o o n a s t h e pump nozzle switches off for the first time,
provided the nozzle has been operated properly. Do not continue refuelling -
otherwise the expansion volume is filled up.
Emergency release of fuel filler flap
If the electric lock is faulty, you can also unlock the fuel filler flap manually.
– Open the boot lid/luggage compartment door.
– Unscrew the clip attaching the right-hand side trim panel and pull the trim panel off the body.
– Pull on the loop in direction of arro w in order to unlock the fuel filler
flap ⇒fig. 171 .
WARNING
When unlocking the fuel filler flap manually, pay attention to sharp edges of
the body - risk of injury!
B1Z-0042HB1Z-0042H
Fig. 171 Luggage
compartment: Emer-
gency release of fuel filler
flap
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