Engine Seat Exeo 2012 Workshop Manual

188Intelligent technology
Practical Tips
Intelligent technology
Electronic Stability Control (ESC)
General Observations
The Electronic Stability Control increases the vehicle's stabil-
ity on the road.
Fig. 152 Centre console
with ESC switch
The ESC is designed to increase the degree of control in situations where
the vehicle 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 (ASR) are all integrated into the Electronic Stabil-
ity Control.
How it works
The ESC control unit processes data from the three integrated systems. It al-
so processes additional inputs provided by other high-precision sensors.
These register the vehicle's rotation about the vertical axis (yaw rate), later-
al acceleration, 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 vehicle is starting to skid), then the ESC
compensates automatically by braking the appropriate wheel.
The forces acting on the braked wheel bring the vehicle back to a stable
condition. 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 ESC works in conjunction with the ABS ⇒ page 189. If a malfunction
should occur in the ABS, the ESC will also stop working.
Deactivating
The ESC is activated automatically when the engine is started and performs
a self-test routine.
The ESC cannot be deactivated. 

191
Intelligent technology
The traction control system (ASR) helps the car to start moving, accelerate
and climb a gradient in slippery conditions where this may otherwise be dif-
ficult or even impossible.
How it works
The ASR works automatically, i.e. without the driver's involvement. With the
aid of the ABS sensors , the ASR monitors the speed of the driven wheels
⇒  page 189. If the wheels start to spin, the engine speed is reduced auto-
matically to match the amount of grip available. The system is active across
the entire speed range.
The ASR works in conjunction with the ABS. If a failure occurs in the ABS,
the ASR will also stop working.
In general, the ASR should be left switched on at all times. It should only be
switched off manually in particular circumstances where a certain amount of
wheel slip may be desirable. Examples:
● when driving with snow chains
● when driving in deep snow or on loose surfaces
● when rocking the vehicle backwards and forwards to free it.
The ASR should be switched on again afterwards as soon as possible.
Note
To ensure that the ASR works properly, all four wheels must be fitted with
identical tyres. The difference in size of the wheels may lead to an unde-
sired reduction in engine power. Also see ⇒  page 247.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications

193
Intelligent technology
Brake servo
The brake servo assists the driver when braking
The brake servo increases 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 engine 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. 
Power steering
Power steering makes it easier to turn the steering wheel
when the engine is running. Power steering assists the driver by reducing the force needed to turn the
steering wheel.
Power steering does not work if the engine is off. In this case the steering
wheel requires much more force to turn.
If the steering is held at its turning limit when the vehicle 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 vehicle 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 vehicle to a
specialised workshop as soon as possible.
● The power steering system requires a special hydraulic fluid. The fluid
reservoir is located at the front of the engine compartment on the left
⇒ page 296. The correct fluid level in the reservoir is important for the pow-
er steering to function properly. The hydraulic fluid level is checked at the
Inspection Service. 
Servotronic*
The servotronic system electronically adjusts the power as-
sisted steering.
In vehicles equipped with servotronic power steering the degree of power
assistance ⇒ page 193 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), as more effort will be required than usual. The fault
should be corrected by a specialised workshop as soon as possible. 
Safety FirstOperating InstructionsPractical TipsTechnical Specifications

194Driving and the environment
Driving and the environment
Running-in Running in a new engine
The engine needs to be run in over the first 1500 km.
Up to 1000 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 kilometres
– 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 consump-
tion reduced. Braking capacity and braking distance
The braking capacity 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 a Technical Service more frequently than recommended in the
Service Plan.
If you drive with wet brakes, for example, after crossing areas of water, in
heavy rainfall or even after washing the vehicle, the effect of the brakes is
lessened as the brake discs are wet or even frozen (in winter). In this case
the brakes should be dried by pressing the brake pedal several times.
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 ap-
plies when the brake pads have to be changed further on.
● If brakes are wet or frozen, or if you are driving on roads which have
been salted, braking power may be lower than normal. 

195
Driving and the environment
WARNING (Continued)
● 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 range (depending on the type of
transmission). This makes use of engine braking and relieves the brakes.
● Never let the brakes “drag” 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.
● If the brake fluid loses its viscosity and is subjected to heavy use, va-
pour bubbles can form in the brake system. This reduces the efficiency of
the brakes.
● Non-standard or damaged front spoilers could restrict the airflow to
the brakes and cause them to overheat. Before purchasing accessories
please observe the relevant instructions ⇒ page 221, Technical modifi-
cations.
● If a brake circuit fails, the braking distance will be increased consider-
ably. Contact a specialised workshop immediately and avoid unnecessa-
ry journeys.

Exhaust gas purification system Catalytic converter*
To maintain the useful life of the catalytic converter
– Use only unleaded petrol with petrol engines, as lead damages
the catalytic converter.
– Do not let the fuel get too low in the tank. –
For engine oil changes, do not replenish with too much engine
oil ⇒ page 230.
– Never tow the vehicle to start it, use jump leads if necessary
⇒ page 285.
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 specialised workshop. In general, the exhaust gas 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 en-
vironment. The catalytic converter can also be damaged by overheating.
WARNING
The catalytic converter reaches very high temperatures! There is a risk of
fire.
● Never park where the catalytic converter could come into contact with
dry grass or flammable 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 sys-
tem. These materials could catch fire when the vehicle is being driven.
CAUTION
Never run the fuel tank completely dry 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 gas 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. 
Safety FirstOperating InstructionsPractical TipsTechnical Specifications

196Driving and the environment
Diesel engine particulate filter*
The diesel engine particulate filter eliminates soot produced
by burning diesel.
The diesel engine particulate filter eliminates most of the soot from the ex-
haust gas system. Under normal driving conditions, the filter cleans itself. If
the driving conditions do not allow the filter to clean itself (for example,
multiple short trips) the filter will be obstructed by dust and pollen and the
indicator  for the diesel engine particulate filter indicator will light up.
This does not represent a fault, it is a warning that indicates that the filter
has not been able to regenerate automatically and that you must carry out a
cleaning cycle, as indicated in ⇒ page 81.
WARNING
● The diesel engine particulate filter may reach extremely high temper-
atures; the vehicle should be parked so that the exhaust pipe does not
come into contact with flammable materials underneath the vehicle. Oth-
erwise there is a risk of fire.
CAUTION
● Your vehicle is not designed to use biodiesel fuel. Never, under any cir-
cumstances refuel with biodiesel. The use of biodiesel fuel could damage
the engine and the fuel system. The addition of biodiesel to diesel by the
diesel producer in accordance with standard EN 590 is authorised and will
not cause damage to the engine or the fuel system.
● Using diesel fuel with a high sulphur content may significantly reduce
the useful life of the diesel particulate filter. Your Technical Service will be
able to tell you which countries have diesel with a high sulphur content. Economical and environmentally friendly
driving
Economical and environmentally friendly driving
Fuel consumption, environmental pollution and wear to the engine, brakes
and tyres depends in large part on your driving style. By adopting an eco-
nomical driving style and anticipating the traffic situation ahead, you can
easily reduce fuel consumption by 10-15%. Some tips on how to help you
reduce pollution while saving money are listed below.
Drive anticipating the traffic situation
A vehicle uses most fuel when accelerating. When you anticipate the situa-
tion, you have to brake less often and, thus, accelerate less. If it is possible,
let the vehicle roll with a
gear engaged, for example, if you see a red light
ahead. The braking effect achieved in this way helps to reduce the wear of
brakes and tyres; emissions and fuel consumption are reduced to zero (dis-
connection due to inertia).
Change gear early to save energy
An effective way of saving fuel is to change up quickly through the gears.
Running the engine at high rpm in the lower gears uses an unnecessary
amount of fuel.
Manual gearbox: Change from first to second gear as quickly as possible.
We recommend that, whenever possible, you change to a higher gear upon
reaching 2000 rpm. Follow the “recommended gear” indication that ap-
pears on the instrument panel ⇒ page 74.
Avoid driving at high speed
We advise you not to drive at the top speed permitted by the vehicle. Fuel
consumption, exhaust emissions and noise levels all increase very rapidly
at higher speeds. Driving at moderate speeds will help to save fuel. 

197
Driving and the environment
Avoid idling
It is worthwhile switching off the engine when waiting in a traffic jam, at lev-
el crossings or at traffic lights with a long red phase. The fuel saved after
only 30 - 40 seconds is greater than the amount of fuel needed to restart
the engine.
The engine takes a long time to warm up when it is idling. Mechanical wear
and pollutant emissions are also especially high during this initial warm-up
phase. It is therefore best to drive off immediately after starting the engine.
Avoid running the engine at high speed.
Periodic maintenance
Periodic maintenance work guarantees that, before beginning a journey,
you will not consume more than the required amount of fuel. A well-serviced
engine gives you the benefit of improved fuel efficiency as well as maxi-
mum reliability and an enhanced resale value.
A badly serviced engine can consume up to 10% more fuel than necessary.
Avoid short journeys
To reduce the consumption and emission of polluting gases, the engine and
the exhaust filtration systems should reach the optimum service tempera-
ture.
With the engine cold, fuel consumption is proportionally higher. The engine
does not warm up and fuel consumption does not normalise until having
driven approximately four kilometres. This is why we recommend avoiding
short trips whenever possible.
Maintain the correct tyre pressures
Bear in mind that keeping the tyres at an adequate pressure saves fuel. If
the tyre pressure is just one bar too low, fuel consumption can increase by
as much as 5%. Due to the greater rolling resistance, under-inflation also
increases tyre wear and impairs handling.
The tyre pressures should always be checked when the tyres are cold.Do not use
winter tyres all year round as they increase fuel consumption by
up to 10%.
Avoid unnecessary weight
Every kilo of extra weight will put up the fuel consumption, so it is worth
checking the luggage compartment occasionally to make sure that no un-
necessary loads are being transported.
A roof rack is often left in place for the sake of convenience, even when it is
no longer needed. At a speed of 100-120 km/h your vehicle will use about
12% more fuel as a result of the extra wind resistance caused by the roof
rack even when it is not in use.
Save electricity
The engine activates the alternator, which produces electricity. With the
need for electricity, fuel consumption is also increased. Because of this, al-
ways turn off electrical components when you do not need them. Examples
of components that use a lot of electricity are: the fan at high speeds, the
rear window heating or the seat heaters*.
Note
● If you vehicle has Start-Stop, it is not recommended to disconnect this
function.
● It is recommended to close the windows when driving at more than
60 km/h
● Do not drive with your foot resting on the clutch pedal, as the pressure
can make the plate spin, more fuel will be used and it can burn the clutch
plate lining, causing a serious fault.
● Do not hold the vehicle on a hill with the clutch, use the foot brake or
hand brake, using the latter to start. The fuel consumption will be lower and
you will prevent the clutch plate from being damaged.
● On descents, use the engine brake, changing to the gear that is more
suitable for the slope. The fuel consumption will be lower and the brakes
will not suffer. 
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199
Trailer towing
Trailer towing Trailer towing
Technical requirements
The towing bracket must meet certain technical require-
ments.
Your vehicle is intended mainly for transporting passengers and luggage.
However, if suitably equipped, it can also be used to tow a trailer or cara-
van.
If your vehicle has been factory-supplied with a towing bracket, all of the
necessary technical and legal aspects for trailing towing have been taking
into account during manufacturing.
Your vehicle is fitted with a 13-pole socket for the electrical connection be-
tween the trailer and the vehicle. If the trailer has a 7-pole connector you
can use an adapter cable. This can be purchased at a Technical Service.
If a towing bracket is to be fitted after the vehicle is purchased, this must be
done according to the instructions of the towing bracket manufacturer
⇒ page 207.
WARNING
If a towing bracket is retrofitted, the installation should be carried out by
a specialised workshop.
● Particularly in high outdoor temperatures, it is not possible to drive
up long steep gradients without a suitable cooling system. The engine
would heat up.
● Incorrect installation can result in a safety risk!
 Notes on towing
There are a number of points which need to be checked be-
fore towing a trailer or caravan.
– Observe the maximum permitted trailer weights ⇒ page 296.
Trailer weight
Never exceed the maximum permitted trailer weight.
If you do not load the trailer up to the maximum permitted trailer weight,
you can then climb correspondingly steeper gradients.
The maximum trailer weights listed are only applicable for altitudes up to
1000 m above sea level. With increasing altitude the engine power and
therefore the vehicle's climbing ability are impaired because of the reduced
air density. The maximum trailer weight has to be reduced accordingly. The
weight of the vehicle and trailer must be reduced by about 10% for every
subsequent 1000 m (or part thereof). This figure refers to the combined
weight of the (loaded) vehicle and (loaded) trailer.
The figures for the drawbar load that appear on the identification plate of
the towing bracket are for certification purposes only. The correct figures for
your specific model, which may be lower than these figures for the towing
bracket, are given in the registration documents and on ⇒ page 289. Also
refer to ⇒ page 296.
Distributing the load
Distribute loads in the trailer so that heavy objects are as near to the axle as
possible. Loads carried in the trailer must be secured to prevent them mov-
ing. 
Safety FirstOperating InstructionsPractical TipsTechnical Specifications

200Trailer towing
Where possible, operate the trailer with the maximum permitted drawbar
load on the ball joint of the towing bracket, but do not exceed the specified
limit.
Tyre pressure
Check the tyre pressures on your vehicle, and adjust for “full load” condi-
tions (refer to the sticker listing the tyre pressures on the door pillar). It may
also be necessary to adjust the tyre pressures on the trailer according to the
recommendations of the trailer manufacturer.
Exterior mirrors
Check whether you can see enough of the road behind the trailer with the
standard mirrors. If this is not the case you should have additional mirrors
fitted. The two exterior mirrors should be fitted on folding arms. Adjust the
mirrors to give sufficient rear vision.
Headlights
Before starting a journey, check the headlight beam settings with the trailer
hitched up. If necessary, alter the height of the headlight beams by means
of the headlight range control. See ⇒ page 119.
Power supply
When you remove the ignition key, the power supply to the trailer is inter-
rupted.
Removable ball joint coupling
Vehicles with a factory-fitted towing bracket are equipped with a removable
ball joint coupling. This is stored in the spare wheel well in the luggage
compartment together with the necessary fitting instructions.
Note
If you frequently tow, we recommend you also have the vehicle serviced be-
tween services. Notes on towing
Towing a trailer involves additional attention by the driver.
Weight distribution
The weight distribution of a loaded trailer with an unladen vehicle is very
unfavourable. However, if this cannot be avoided, drive extra slow to allow
for the unbalanced weight distribution.
Speed
The stability of the vehicle and trailer is reduced with increasing speed.
Therefore, it is advisable not to drive at the maximum permissible speed in
unfavourable road, weather or wind conditions. This especially applies
when driving downhill.
You should always reduce speed immediately if the trailer shows the slight-
est sign of swaying. Never try to stabilise the trailer by accelerating.
Anticipate hazards and brake in good time. If towing a trailer with an inertia
brake, first brake gently and then harder. This will prevent brake tapping by
the trailer wheels when they lock. Select a low gear in due course before go-
ing down a steep downhill. This enables you to use the engine braking to
slow down the vehicle.
Swaying and pitching can be reduced by stabiliser aids. We recommend
having stabiliser aids installed when towing trailers with a high trailer
weight. They can be purchased and installed at a Technical Service.
Reheating
When climbing long hills in hot weather with the engine running fast in low
gear, you should keep an eye on the coolant temperature gauge ⇒ page 60.
Reduce speed immediately if the needle moves to the right end of the scale.
If the temperature warning lamp  in the instrument panel should start
flashing, stop the vehicle and let the engine cool down by running it at
idling speed for a few minutes. 

209
Vehicle maintenance and cleaning
Vehicle maintenance and cleaning General notes
Regular washing and care help maintain the value of your
vehicle.Vehicle maintenance
Regular care and washing help to maintain the value of the vehicle. This
may also be one of the requirements for acknowledging warranty claims in
the event of bodywork corrosion or paint defects.
The best way to protect your vehicle against the harmful effects of the envi-
ronment is through correct maintenance and frequent washing. The longer
substances such as insect remains, bird droppings, resinous tree sap, road
dirt, industrial deposits, tar, soot or road salt and other aggressive materi-
als remain on the vehicle, the more damage they do to the paintwork. High
temperatures (for instance in strong sunlight) further intensify the corrosive
effect.
After winter, a period when salt is put on the roads, it is important to have
the underside of the vehicle washed thoroughly.
Products for vehicle maintenance
Car care products are available in your Technical Services. Keep the product
instructions until you have used them up.
WARNING
● Car care products can be toxic. Because of this, they must always be
kept closed in their original container. Keep them out of the reach of chil-
dren. Failure to comply could result in poisoning.
● Always read and observe the instructions and warnings on the pack-
age before using vehicle care products. Improper use could cause health
problems or damage the vehicle. The use of certain products may pro-
duce noxious vapours; they should be used in well ventilated areas.
● Never use fuel, turpentine, engine oil, nail varnish remover or other
volatile fluids. These are toxic and highly flammable. Risk of fire and ex-
plosion.
● Before washing your vehicle, or carrying out any maintenance, switch
the engine off, apply the handbrake firmly and remove the key from the
ignition.
CAUTION
Never attempt to remove dirt, mud or dust if the surface of the vehicle is dry.
Never use a dry cloth or sponge for cleaning purposes. This could damage
the paintwork or the windows of your vehicle. Soak dirt, mud or dust with
plenty of water.
For the sake of the environment
● When purchasing products for your vehicle maintenance, select the
ones which are not harmful to the environment.
● The waste from car care products should not be disposed of with ordina-
ry household waste. Observe the disposal information on the package. 
Safety FirstOperating InstructionsPractical TipsTechnical Specifications