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Intelligent technology183
Safety First
Controls and equipment
Practical tips
Technical Data
Practical tipsIntelligent technologyElectronic stabilisation programme (ESP)General notes
The electronic stabilisation programme increases the
vehicle's stability on the road.The ESP is designed to increase the degree of control in situations where the
car approaches the limits of adhesion, especially when accelerating and
cornering. It reduces the risk of skidding and improves stability in all road
conditions. The system is active across the entire speed range. The anti-lock brake system (ABS), the electronic differential lock (EDL) and
the traction control system (TCS) are all integrated into the electronic stabili-
sation programme.
How it works
The ESP control unit processes data from the three integrated systems. It also
processes additional inputs provided by other high-precision sensors. These
register the vehicle's rotation about the vertical axis (yaw rate), lateral accel-
eration, brake pressure and steering wheel angle.
The system uses the steering wheel angle and road speed to calculate the
changes of direction desired by the driver, and constantly compares them
with the actual behaviour of the vehicle. If the desired course is not being
maintained (for instance, if the car is starting to skid), then the ESP compen-
sates automatically by braking the appropriate wheel.
The forces acting on the braked wheel bring the car back to a stable condi-
tion. If the vehicle
over swerves (tendency of the rear to leave the road), the
brakes will act on the front wheel facing the outside of the bend. If the vehicle
under swerves (tendency to leave the bend), the braking force is applied to
the rear wheel facing the inside of the bend.
The ESP works in conjunction with the ABS ⇒page 184. If a malfunction
should occur in the ABS, the ESP will also be out of action.
Disabling
The ESP is enabled automatically when the engine is started and performs a
self-test routine.
Fig. 151 Centre console
with ESP switch
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Intelligent technology
184If required, the ESP can also be enabled and disabled manually by briefly
pressing the switch ⇒page 183, fig. 151. The ESP warning lamp lights
up when the system is switched off, see ⇒page 68.
In general, the ESP should be left switched on at all times. In particular
circumstances where a certain amount of wheel slip is desirable, it may be
advisable to switch off the ESP. Examples:•when driving with snow chains•when driving in deep snow or on loose surfaces•when rocking the car backwards and forwards to free it.
The ESP should be switched on again afterwards as soon as possible.WARNING
The ESP is not able to overcome the physical limits of adhesion. Even with
ESP, you should always adjust your speed to suit the conditions. Please
b ea r t h is i n m i n d , e s p e ciall y o n w e t o r s l i pp e r y roa d s u r fa ces . D o n o t l e t t h e
extra safety features tempt you into taking any risks when driving. Failure
to do so could result in an accident.Anti-lock brake system (ABS)
ABS prevents the wheels from locking up under braking.The anti-lock brake system (ABS) is an important part of the car's active safety
system. However, the ABS will not necessarily guarantee shorter stopping
distances in all conditions. For instance, on loose gravel or fresh snow on top
of an icy surface (conditions which anyway require extreme care and reduced
speed), the stopping distance with ABS may even be slightly longer. How the ABS works
The system runs an automatic self-check when the car reaches a road speed
of about 6 km/h. This may be accompanied by a noise from the ABS pump.
When one of the wheels is turning very slowly in relation to the road speed
and is close to locking up, the system will reduce the pressure in the brake
line to this wheel. The driver is made aware of this adjustment process by a
vibration of the brake pedal
and an audible noise. This is a deliberate
warning to the driver that one or more of the wheels is tending to lock up and
the ABS control function has intervened. In this situation it is important to
keep the brake pedal fully depressed so the ABS can regulate the brake appli-
cation, but do not “pump” the brake pedal.
WARNING
The grip provided by ABS is still subjec t to the physical limits of adhesion.
Always bear this in mind, especially on wet or slippery roads. If you notice
that the ABS is working (to counteract locked wheels under braking), you
should reduce speed immediately to suit the road and traffic conditions. Do
not let the extra safety features tempt you into taking any risks when
driving. Failure to do so could result in an accident.
Note
If a malfunction should occur in the ABS, this is indicated by a warning lamp
⇒ page 67.Brake assist system
The brake assist system helps the driver to achieve optimum
braking effect.The brake assist system helps to increase braking power and thus to achieve
a shorter stopping distance. If the driver presses the brake pedal very quickly,
ESP
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Intelligent technology185
Safety First
Controls and equipment
Practical tips
Technical Data
the brake assist system automatically boosts the braking force to the
maximum level, up to the point where the anti-lock brake function (ABS) inter-
venes to stop the wheels from locking. You should then keep the brake pedal
pressed until the vehicle has braked to the required speed. The brake assist
system switches itself off as soon as you release the brake pedal.
The brake assist system will not be operative if there is a malfunction in the
ABS or the ESP.
WARNING
Please remember that the accident risk always increases if you drive too
fast, especially in corners or on a slippery road, or if you follow too close
behind the vehicle in front of you. An increased accident risk cannot be
compensated even by the brake assist system. Risk of accident.Electronic differential lock (EDL)
The electronic differential lock prevents the loss of traction
caused if one wheel starts spinning.General notes
The electronic differential lock (EDL) helps the car to start moving, accelerate
and climb a gradient in slippery conditions where this may otherwise be diffi-
cult or even impossible.
How it works
The EDL works automatically, i.e. without the driver's involvement. With the
aid of the ABS sensors, the system monitors the rotational speed of the
driven wheels ⇒
page 184. If a considerable difference in revs is detected
(approx. 100 rpm) in the speed of the driven wheels, e.g. when only one part
of the surface supporting the wheels is slippery, the system applies the brake
to slow down the skidding wheel so that more of the power is directed to the other wheels. The systems works up to a speed of approx. 80 km/h. The
system will make noises while it is working.
Moving away from a standstill
If one wheel has less grip and starts spinning (for instance, if one of the
driven wheels is on ice), keep pressing the accelerator gradually until the car
starts moving.
Overheating of the brakes
To prevent the brake disk of the braked wheel from overheating, the EDL cuts
out automatically if subjected to excessive loads. In this case, the vehicle will
continue to run and will have the same running properties as those of another
without EDL.
The EDL will switch on again automatically when the brake has cooled down.
WARNING
•When accelerating on a uniformly slippery surface (for instance all four
wheels on ice or snow), press the accelerator gradually and carefully.
Despite EDL, the driven wheels may otherwise start to spin. This could
impair the car's stability. Risk of accident.•Even with EDL, you should always adjust your speed to suit the condi-
tions. Do not let the extra safety features tempt you into taking any risks
when driving. Failure to do so could result in an accident.Note
If the ABS warning lamp lights up, this can also mean there is a fault in the
EDL. Please take the vehicle to a specialist garage as soon as possible.
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Intelligent technology
186Traction control system (TCS)
The traction control system prevents the drive wheels from
spinning when the car is accelerating.General notes
The traction control system (TCS) is one of the functions incorporated in the
electronic stabilisation programme (ESP).
The traction control system (TCS) helps the car to start moving, accelerate or
climb a gradient in slippery conditions where this may otherwise be difficult
or even impossible.
How it works
The TCS acts automatically, i.e. without the driver's intervention. With the aid
of the ABS sensors ⇒page 184, the TCS monitors the speed of the driven
wheels. If the wheels start to spin, the engine power is reduced automatically
to match the amount of grip available. The system is active across the entire
speed range.
The TCS works in conjunction with the ABS. If a malfunction occurs in the ABS,
the TCS will also be inoperative.
Note
To ensure that the TCS works properly, all four wheels must be fitted with
identical tyres. The difference in size of the wheels may lead to an undesired
reduction in engine power. Also see ⇒page 241.
BrakesGeneral notesNew brake pads
New brake pads do not provide optimal performance during the first 200 km
they must be “run in”. However, the reduced braking capacity may be
compensated by pressing on the brake pedal a little harder. Avoid over-
loading the brakes during run-in.
Wear
T h e r a t e o f we a r o n t h e brake pads depends a great deal on how you drive and
the conditions in which the vehicle is operated. Negative factors are, for
instance, city traffic, frequent short trips or hard driving with abrupt starts
and stops.
Wet roads; road salt
In certain conditions, such as in heavy rain, or after washing the car or driving
through water, the full braking effect can be delayed by moisture (or in winter
by ice) on the discs and brake pads. The brakes should be “dried” by pressing
the pedal to restore full braking effect.
When the velocity is over 80 km/h windscreen wipers are on, the brake
system moves the pads towards the brake discs for a few seconds. This
occurs - without warning to the driver - at regular intervals and requires a
more rapid response from the brakes when driving on wet roads.
The effectiveness of the brakes can also be temporarily reduced if the car is
driven for some distance without using the brakes when there is a lot of salt
on the road in winter. In this case, the layer of salt on the brake discs and pads
has to wear off before braking.
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Intelligent technology187
Safety First
Controls and equipment
Practical tips
Technical Data
Corrosion
There may be a tendency for dirt to build up on the brake pads and corrosion
to form on the discs if the car is used infrequently, or if you only drive low
mileages without using the brakes very much.
If the brakes are not used frequently, or if rust has formed on the disks, it is
advisable to clean off the pads and disks by braking firmly a few times from a
moderately high speed
⇒.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may mean that
one of the two brake circuits has failed. Drive immediately to the nearest qual-
ified workshop and have the fault rectified. On the way to the dealer, be
prepared to use more pressure on the brake pedal, and allow for longer stop-
ping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is too low.
The brake fluid level is monitored electronically.
WARNING
When applying the brakes to clean off deposits on the pads and discs,
select a clear, dry road. Be sure not to inconvenience or endanger other
road users. Risk of accident.
Caution
•Never let the brakes “drag” by leaving your foot on the pedal when you do
not really intend to brake. This overheats the brakes, resulting in longer stop-
ping distances and greater wear.•Before driving down a long, steep gradient, it is advisable to reduce speed
and change to a lower gear (or move the selector lever to a lower gear position
if your car has automatic transmission). This makes use of engine braking and prolongs the service life of the brakes. If you still have to use the brakes,
it is better to brake firmly at intervals than to apply the brakes continuously.
Note
If you wish to equip the car with accessories such as a front spoiler or wheel
covers, it is important that the flow of air to the front wheels is not obstructed,
otherwise the brakes can overheat.Brake servo
The brake servo assists the driver when brakingThe brake servo amplifies the pressure you apply to the brake pedal. The
brake servo works only when the engine is running.
WARNING
Ensure the vehicle does not move while in neutral, when the motor is
stopped. Failure to do so could result in an accident.
Note
If the brake servo is not working, e.g. because the vehicle has to be towed or
because it is broken, you will have to press the brake pedal considerably
harder to make up for the lack of servo assistance.
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188Power steeringThe power steering assists the driver when turning the
steering wheel (with the engine running).The power steering assists the driver by reducing the force needed to turn the
steering wheel.
The power steering does not work if the engine is off. In this case the steering
wheel is very hard to turn.
If the steering is held at its turning limit when the car is stationary, this will
place an excessive load on the power steering system. Turning the steering
wheel to its limit places a load on the system, which causes noise. It will also
reduce the idling speed of the engine.
Caution
When the engine is running, do not turn the steering wheel to its limit for
more than 15 seconds. Otherwise, there is a risk of damaging the power
steering.
Note
•If the power steering should fail at any time or the engine is switched off
(for instance when being towed), the car can still be steered. However, more
effort will be required to turn the steering wheel.•If the system is leaking or malfunctioning, please take the car to a quali-
fied workshop as soon as possible.•The power steering requires a special hydraulic fluid. The fluid reservoir is
located at the front of the engine compartment on the left ⇒ page 289. The
correct fluid level in the reservoir is important for the power steering to func-
tion properly. The hydraulic fluid level is checked at the Inspection Service.
ServotronicThe servotronic system electronically adjusts the degree of
power assistanceIn cars equipped with servotronic power steering the degree of power assist-
ance ⇒page 188 is adjusted electronically according to road speed.
If a fault should occur in the servotronic system, the power steering will still
operate. The degree of power assistance will, however, no longer adapt to
different speeds. If the electronic regulating system is not working properly,
this is most noticeable when turning the steering wheel at low speeds (for
instance when parking) – more effort will be required than usual. The fault
should be corrected by a qualified workshop as soon as possible.
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Driving and the environment189
Safety First
Controls and equipment
Practical tips
Technical Data
Driving and the environmentRunning-inRunning in a new engine
The engine needs to be run-in over the first 1,500 km.Up to 1,000 kilometres
– Do not drive at speeds of more than 2/3 the maximum speed.
– Do not accelerate hard.
– Avoid high engine revolutions.
– Do not tow a trailer.
From 1000 to 1500 km
– Speeds can be gradually increased to the maximum road speed
or maximum permissible engine speed (rpm).During its first few hours of running, the internal friction in the engine is
greater than later on, when all the moving parts have bedded in.
For the sake of the environment
If the engine is run in gently, its life will be increased and its oil consumption,
reduced.
Braking effect and braking distance
The braking effect and braking distance are influenced by
driving situations and road conditions.The efficiency of the brakes depends directly on the brake pad wear. The rate
of wear of the brake pads depends to a great extent on the conditions under
which the vehicle is operated and the way the vehicle is driven. If you often
drive in town traffic, drive short distances or have a sporty driving style, we
recommend that you have the thickness of your brake pads checked by an
Authorised Service Centre more frequently than recommended in the Ser vice
Schedule.
If you drive with wet brakes, for example, after crossing areas of water, in
heavy rainfall or even after washing the car, the effect of the brakes is less-
ened as the brake discs are wet or even frozen (in winter): The brakes should
be “dried” by pressing the pedal to restore full braking effect.
WARNING
Longer braking distances and faults in the brake system increase the risk
of accidents.•New brake pads must be run in and do not have the correct friction
during the first 200 km. However, the reduced braking capacity may be
compensated by pressing on the brake pedal a little harder. This also
applies when new brake pads are fitted.•If brakes are wet or frozen, or if you are driving on roads which have
been gritted with salt, braking power may set in later than normal.•On steep slopes, if brakes are excessively used, they will overheat.
Before driving down a long steep slope, it is advisable to reduce speed and
change down into a lower gear (or move the selector lever to a lower gear if
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Driving and the environment
190your vehicle has automatic transmission). This makes use of engine
braking and relieves the brakes.•Never let the brakes “slip” by applying light pressure. Continuous
braking will cause the brakes to overheat and the braking distance will
increase. Apply and then release the brakes alternately.•Never let the vehicle run with the engine switched off. The braking
distance is increased considerably when the brake servo is not active.•Very heavy use of the brakes may cause a vapour lock if the brake fluid
is left in the system for too long. This impairs the braking effect.•Non-standard or damaged front spoilers could restrict the airflow to the
brakes and cause them to overheat. Observe the relevant instructions
before purchasing accessories ⇒ page 214, “Technical modifications”.•If a brake circuit fails, the braking distance will be increased consider-
ably. Contact a qualified workshop immediately and avoid unnecessary
journeys.
Exhaust gas purification systemCatalytic converter*To conserve the useful life of the catalytic converter
– Always use unleaded petrol.
– Do not let the fuel get too low in the tank.
– For engine oil changes, do not replenish with too much engine oil ⇒page 224. – Never tow the vehicle to start it, use jump leads if necessary
⇒page 279.
If you notice misfiring, uneven running or loss of power when the vehicle is
moving, reduce speed immediately and have the vehicle inspected at the
nearest qualified workshop. In general, the exhaust warning lamp will light
up when any of the described symptoms occur ⇒page 66. If this happens,
unburnt fuel can enter the exhaust system and escape into the environment.
The catalytic converter can also be damaged by overheating.
WARNING
The catalytic converter reaches very high temperatures! Fire hazard!•Never park where the catalytic converter could come into contact with
dry grass or inflammable materials under the vehicle.•Do not apply additional underseal or anti-corrosion coatings to the
exhaust pipes, catalytic converter or the heat shields on the exhaust
system. These materials could catch fire when the vehicle is being driven.Caution
Never fully drain the fuel tank because the irregularity of the fuel supply may
cause ignition problems. This allows unburnt fuel to enter the exhaust
system, which could cause overheating and damage the catalytic converter.
For the sake of the environment
Even when the emission control system is working perfectly, there may be a
smell of sulphur from the exhaust under some conditions. This depends on
the sulphur content of the fuel used. Quite often the problem can be solved
by changing to another brand of fuel.
WARNING (continued)
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