ESP AUDI A4 2008 B8 / 4.G Repair Manual

Seat belts 198The height of the front seat on your vehicle can be adjusted in order
to match the position of the seat belt to your height.
WARNING
•
The diagonal part of the belt should never be positioned across
the neck, but roughly over the centre of the shoulder; it should fit
closely against the upper part of the body. The lap part of the belt
must be worn tightly across the hips, and not over the abdomen
⇒page 197, fig. 210. Pull the belt tight if necessary to take up any
slack.
•
Always make sure that belt is positioned properly. Incorrectly
worn seat belts can give rise to injuries even in a minor collision.
•
Seat belts worn too loose can result in injuries because they
allow excessive forward movement in a crash; the occupant will
be brought to a sudden stop by the belt webbing.
Wearing and adjusting the seat belts during pregnancy
To afford the best protection for the unborn child it is
important for the mother to wear the seat belt properly at
all times.
Women should always ensure they adjust the seat belt
correctly during pregnancy.
– Adjust the front seat and head restraint correctly before
putting on the seat belt ⇒page 73, “Seats and storage”.
– To fasten the belt, take hold of the latch plate and pull it
slowly down across your chest. Wear the lap portion of
the seat belt as low as possible over the hips so that there
is no pressure on the stomach ⇒fig. 211, ⇒.
– Insert the latch plate into the buckle for the appropriate
seat and push it down until it is securely locked with an
audible click ⇒page 197, fig. 209.
– Pull the belt to check that it is now securely fastened.
WARNING
During pregnancy, women should especially make sure to wear
the lap portion of the seat belt as low as possible across the hips
so that there is no pressure on the stomach.
Fig. 211 Positioning
seat belts during preg-
nancy
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Airbag system 202•
Do not remove the front seats.
•
The airbag system can only be activated once; if the airbag has
been triggered, the system must be replaced. Should the airbag
system or airbag modules have to be replaced, the qualified work-
shop carrying out the replacement will document all details in the
appropriate section of the Service Schedule.
•
If you sell the vehicle, please remember to pass on the
complete Service Wallet to the new owner. If any of the airbags
have been deactivated, it is important that the new owner is also
given the relevant documents.
•
The relevant safety requirements must be observed when the
vehicle or components of the airbag or belt tensioner systems are
scrapped.
•
In an accident in which one or more airbags are triggered the
alternator and the starter are - for safety reasons - both discon-
nected from the battery via a pyrotechnic circuit breaker.
−Any repairs to the pyrotechnic circuit breaker must always
be performed by a qualified workshop (accident risk).
−The relevant safety requirements must be observed when
the vehicle or the circuit breaker are scrapped.
When are the airbags triggered?
The airbag system is triggered in collisions with a severe
impact.The airbag system is designed so that the airbags for the driver and
front passenger are triggered in a severe frontal collision.
In severe side collisions the side airbags on the impact side of the
vehicle are triggered together with the head-protection airbag.
The front airbags, side airbags and one of the head-protection
airbags may be triggered together in certain types of accident.The airbag system is not triggered in minor frontal or side collisions,
or in rear collisions or if the car overturns. In these situations the
occupants are protected by wearing the seat belts.
Factors determining the triggering response
It is not possible to define the exact triggering response of the
airbag system in all possible situations, since the circumstances in
different types of accident will vary considerably. Important factors
include, for example, the nature (hard or soft) of the object which
the car hits, the angle of impact, vehicle speed and so on.
Whether the airbags are triggered depends primarily on the vehicle
deceleration rate resulting from the collision. By processing the
signals from the sensors located in the vehicle, the electronic
control unit is immediately able to evaluate the severity of the colli-
sion and activate the restraint systems accordingly. If the decelera-
tion rate is below the predefined reference value in the control unit
the airbags will not be triggered, even though the accident may
cause extensive damage to the car.
Note
The airbag releases a fine dust when it inflates. This is quite normal
and does not mean there is a fire in the vehicle.
WARNING (continued)
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Airbag system209
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
The key-operated switch for deactivating the front
passenger's airbag is located in the glove box ⇒fig. 222.
– To deactivate the front passenger's airbag, insert the
ignition key into the switch and turn it to position .
– The front passenger's airbag can be reactivated by
turning the key to position .Deactivating front passenger's airbag when a child
safety seat is in use
If you have no alternative but to install a rearward-facing child safety
seat on the front passenger's seat you must deactivate the front
passenger's airbag beforehand.
We recommend, however, that child seats should be only fitted on
the rear seat so that the front passenger's airbag can remain func-
tional and provide protection in an accident ⇒page 210.
Monitoring of airbag system
The airbag warning lamp will light up for a few seconds every time
the ignition is switched on.
If the front passenger's airbag has been deactivated via the key-
operated switch, the indicator lamp “PASSENGER AIRBAG OFF” will
light up constantly as a reminder ⇒page 209, fig. 223. Please refer
also to the description of the
 warning lamp in the instrument
cluster ⇒page 17.When the front passenger's airbag is deactivated using the key-
operated switch, the seat belt warning lamp for the front passenger
 ⇒page 18 is also switched off.
WARNING
•
If you have no alternative but to install a rearward-facing child
seat on the front passenger's seat, the front passenger's airbag
must be deactivated beforehand. Potentially fatal injuries to the
child can result if the front passenger's airbag is not deactivated!
⇒page 211, “Using a child safety seat on the front passenger's
seat”
•
If you have deactivated the front passenger's airbag, reactivate
it as soon as the child seat is no longer needed so that the airbag
can continue to give the required protection.
•
It is the driver's responsibility to ensure that the key-operated
switch is set to the correct position.Note
All the other airbags in the car will remain functional if the front
passenger's airbag has been deactivated with the key-operated
switch.
Fig. 223 Lamp indi-
cates that front
passenger's airbag has
been deactivated via
key-operated switch
AOFF
AON
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Child safety 210Child safetyPoints to remember if children are
travelling in the carIntroduction
Statistics show that children are generally safer on the
rear seat than on the front passenger's seat.Children under 12 years of age should normally travel on the rear
seat
2). Children travelling on the rear seat must use a child restraint
system or the seat belts provided, depending on their age, height
and weight. For safety reasons, the child restraint system should be
installed behind the front passenger's seat.
The physical principles involved and the forces acting in a collision
apply to children just as much as adults ⇒page 195, “Forces acting
in a collision”. But, unlike adults, children do not have fully devel-
oped muscle and bone structures. This means that children are
subject to a greater risk of injury.
To reduce this risk, children must always use special child restraint
systems when travelling in the car.
Use only child restraint systems which are officially approved under
the European standard ECE R 44 and are suitable for the child. ECE R
refers to the Economic Commission of Europe Recommendation,
which categorises child restraint systems in 5 groups ⇒page 213,
“Child seat categories”. Child restraints that have been tested and
approved under the ECE R 44 standard bear the ECE-R 44 test mark
on the seat (the letter E in a circle with the test number below it).
We recommend using child restraint systems from the range of
Audi Genuine Accessories available from Audi dealers. The
“Huckepack” range includes suitable restraint systems for all ages. These systems have been specially developed and tested for use in
Audi vehicles and comply with the ECE-R 44 standard.
Follow the manufacturer's instructions and observe any statutory
requirements when installing and using child restraints ⇒ in
“Important safety notes for using child safety seats”.
Important safety notes for using child safety seats
Correct use of child safety seats can help to reduce the
risk of injury in an accident.
WARNING
•
All vehicle occupants, especially children, must wear a seat
belt while the vehicle is in motion.
•
Children who are less than 1.5 metres tall must not wear a
normal seat belt without a child restraint, as this could cause inju-
ries to the abdominal and neck areas.
•
Babies and children must never travel on another occupant's
lap.
•
A suitable child safety seat can protect your child ⇒page 213,
“Child safety seats”.
•
Never allow two children to occupy one child safety seat.
•
Never leave a child without supervision in a child safety seat.
•
Never allow a child to travel in the car without a suitable child
restraint.
•
Never allow a child to stand up or kneel on a seat while the car
is moving. In an accident, the child could be catapulted through
the car, causing possibly fatal injuries to itself and other occu-
pants.
2)Observe any restrictions or regulations to the contrary.
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Intelligent technology 222Intelligent technologyElectronic stabilisation program (ESP)DescriptionESP increases the car's stability. It reduces the tendency to skid and
improves the stability and roadholding of the vehicle. ESP detects
critical handling situations, such as understeer, oversteer and
wheelspin on the driven wheels. It stabilises the vehicle by braking
individual wheels or by reducing the engine torque. The warning
lamp
 in the instrument cluster starts flashing as soon as the ESP
intervenes.
The ESP incorporates the functions of the anti-lock brake system
(ABS), the traction control system (ASR), the electronic differential
lock (EDL) and the dynamic steering*.
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up under braking until the
vehicle has reached a virtual standstill. You can continue to steer the
vehicle even when the brakes are on full. Keep your foot on the brake
pedal and do not pump the brakes. You will feel the brake pedal
pulsate while the anti-lock brake system is working.
Brake assist system
The brake assist system can speed up the braking process and
shorten the braking distance. It automatically boosts the braking
force if you press the brake pedal quickly in an emergency. On vehi-
cles with adaptive cruise control*, the brake assist system will build
up a small amount of pressure in the hydraulic brake system if it
senses that you are too close to the vehicle in front.
Traction control system (ASR)
In the event of wheelspin, the traction control system reduces the
engine torque to match the amount of grip available. This helps the
car to start moving, accelerate or climb a gradient.Electronic differential lock (EDL)
When the EDL detects wheelspin, it brakes the spinning wheel and
directs the power to the other driven wheel (or wheels on quattro*
versions). This function is active up to about 100 km/h.
To prevent the disc brake of the braked wheel from overheating, the
EDL cuts out automatically if subjected to excessive loads. The
vehicle can still be driven. The EDL will switch on again automati-
cally when the brake has cooled down.
Dynamic steering*
On vehicles with dynamic steering*, the ESP can also intervene in
the steering to stabilise the vehicle in critical situations.
WARNING
•
The grip provided by the ESP, ABS, ASR, EDL and dynamic
steering* systems is still subject to the physical limits of adhesion.
Always bear this in mind, especially on wet or slippery roads. If
you notice the systems cutting in, you should reduce your speed
immediately to suit the road and traffic conditions. Do not let the
extra safety provided tempt you into taking any risks when driving
– this can cause accidents.
•
Please remember that the accident risk always increases if you
drive fast, especially in corners or on a slippery road, or if you
follow too close behind the vehicle in front of you. Please bear in
mind that even ESP, ABS, brake assist, EDL, ASR and dynamic
steering* cannot compensate for the increased accident risk.
•
When accelerating on a uniformly slippery surface (for instance
all four wheels on ice or snow), press the accelerator gradually and
carefully. The driven wheels may otherwise start to spin (in spite
of the integrated control systems), which would impair the car's
stability and could lead to an accident.
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Intelligent technology223
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
•
To ensure that the ASR works properly, all four wheels must be
fitted with identical tyres. Any differences in the rolling radius of the
tyres can cause the system to reduce engine power when this is not
desired.
•
Should a malfunction occur in the ABS or EDL, both the ABS
warning lamp
 and the ESP warning lamp
 ⇒page 19 will light
up.
•
In the event of a malfunction in the ESP system, the warning
lamp  ⇒page 17 will light up.
•
If a malfunction should occur in the ABS, the ESP, EDL and ASR
will also be out of action.
•
The systems can make noises when they intervene.
Switching on and off
The ESP is switched on automatically when the engine is
started.
Switching off the traction control system (ASR)
In particular circumstances, it may be advisable to switch off the
traction control system (ASR) to allow a certain amount of wheel
slip. For example:•
Rocking the car backwards and forwards to free it
•
Driving in deep snow or on loose surfaces
•
Driving with snow chains
Press the button briefly ⇒fig. 232 or ⇒fig. 233. The
warning lamp
 will light up and the message ASR off will appear
in the driver information system display.
The traction control system (ASR) can only be switched off at speeds
below 50 km/h on vehicles with front-wheel drive. At 70 km/h it will
switch on again automatically. The ASR can be deactivated at any
speed on vehicles with four-wheel drive.
Switching off the ESP
Press the button for longer than 3 seconds. The ESP
warning lamp  will light up and the message ESP switched off will
appear in the display. The ASR is also deactivated when the ESP is
switched off.
Switching on
Press the button again. The message ESP/ASR on will
appear briefly on the display.
Fig. 232 Version A:
Centre console
(bottom), ESP OFF
button
Fig. 233 Version B:
Centre console (top),
ESP OFF button
ESP OFFESP OFFESP OFF
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Intelligent technology 224
WARNING
You should switch off the ESP only if your driving ability and traffic
conditions allow you to do so safely. Please note that, when the
ASR and ESP are switched off, the driven wheels may start to spin,
causing the vehicle to lose grip, in particular on slippery or wet
roads - danger of skidding!
Note
The ASR and ESP cannot be switched off when the adaptive cruise
control (ACC)* is on.BrakesNew brake pads
New brake pads do not give full braking effect for the first 400 km,
they must first be “bedded in”. However, you can compensate for
the slightly reduced braking effect by applying more pressure on
the brake pedal. Avoid placing a heavy load on the brakes during the
running-in period.
We ar
The rate of wear on the 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
When you are driving at a speed higher than 80 km/h and have the
windscreen wipers switched on the brake pads are very briefly
brought into contact with the brake discs. This automatic process
which goes unnoticed by the driver is carried out at regular intervals
and is intended to improve braking response in wet conditions.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.
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. The layer of salt that accu-
mulates on the discs and pads can be removed with a few cautious
brake applications.
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 corrosion has formed on
the discs, it is advisable to clean off the pads and discs 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 immedi-
ately to the nearest qualified 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 stopping 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.
Brake servo
The brake servo amplifies the pressure you apply to the brake pedal.
It only works when the engine is running.
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Intelligent technology 226Applies to vehicles: with four-wheel driveFour-wheel drive (quattro
®)
On quattro models the engine power is distributed to all
four wheelsGeneral notes
On four-wheel drive vehicles, the engine power is distributed to all
four wheels. The distribution of power is controlled automatically
according to your driving style and the road conditions. Also refer
to ⇒page 222, “Description”.
The four-wheel drive is specially designed to complement the supe-
rior engine power of your Audi. This combination gives the car
exceptional handling and performance capabilities – both on
normal roads and in more difficult conditions, such as snow and ice.
Even so (or perhaps especially for this reason), it is important to
observe certain safety points ⇒.
Winter tyres
Thanks to its four-wheel drive, your car will have plenty of traction
in winter conditions, even with the standard tyres. Nevertheless, we
still recommend that winter tyres or all-season tyres should be fitted
on all four wheels when winter road conditions are expected, mainly
because this will give a better braking response.
Snow chains
On roads where snow chains are mandatory, this also applies to cars
with four-wheel drive ⇒page 273, “Snow chains”.
Replacing tyres
On vehicles with four-wheel drive, all four tyres must have the same
rolling circumference. Also avoid using tyres with varying tread
depths ⇒page 270, “Replacing wheels and tyres”.Off-roader?
Your Audi does not have enough ground clearance to be used as an
off-road vehicle. It is therefore best to avoid rough tracks and
uneven terrain as much as possible.
WARNING
•
Even with four-wheel drive, you should always adjust your
speed to suit the conditions. Do not let the extra safety provided
tempt you into taking any risks when driving – this can cause acci-
dents.
•
The braking ability of your car is limited by the grip of the tyres.
In this respect, your car is no different from a car without four-
wheel drive. So do not be tempted to drive too fast on icy or slip-
pery roads just because the car still has good acceleration in these
conditions (accident risk).
•
On wet roads bear in mind that the front wheels may start to
“aquaplane” and lose contact with the road if the car is driven too
fast. If this should happen, there will be no sudden increase in
engine speed to warn the driver, as with a front-wheel drive car. So
do not drive too fast in the wet: adjust your speed to suit the
conditions (accident risk).
Power managementThis system helps to ensure reliable starting
The power management controls the distribution of elec-
trical energy and thus helps to ensure that there is always
enough power available to start the engine.If a vehicle with a conventional electrical system is left parked for a
long time, the battery will gradually lose its charge because certain
electrical equipment (such as the immobiliser) continues to draw
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Intelligent technology 228With the engine switched off
If you listen to the radio or use the other MMI functions when the
engine is not running, this will discharge the battery.
The MMI display will show this warning message before the battery
power drops to a level where the starting ability is impaired.
Please start engine, otherwise system will switch off
in 3 minutes.
This message warns you that the system you are using will be
switched off automatically after 3 minutes. You should therefore
start the engine if you wish to continue using the system.
When the engine is running
Although the alternator generates electrical power, the battery can
still become discharged while the vehicle is being driven. This can
occur when a lot of power is being consumed but only a small
amount supplied, especially if the battery is not fully charged
initially.
To restore the necessary energy balance, the system will then
temporarily shut off the electrical components that are using a lot
of power, or reduce the current they are consuming. Heating
systems in particular use a large amount of electrical power. If you
notice, for instance, that the seat heating* or the rear window
heater is not working, they may have been temporarily switched off
or regulated to a lower heat output. These systems will be available
again as soon as sufficient electrical power is available.
You may also notice that the engine runs at a slightly faster idling
speed. This is quite normal, and no cause for concern. The increased
idling speed allows the alternator to meet the greater power
requirement and charge the battery at the same time.
Driver message in the instrument cluster displayIf battery power drops to a level at which you may encounter prob-
lems when starting the engine, the following message will appear
in the instrument cluster display:
 Low battery charge: Battery will be charged while driving
This message reminds you that the starting reliability may be
impaired. The message will disappear as soon as you set off and the
battery is charged.
Message comes on and goes out again
If the message appears in the display after the ignition is switched
on or while driving, and goes out again after a period of time, the
battery has been charged up again sufficiently while the vehicle was
being driven.
Message comes on and does not go out
If the message appears in the display after the ignition is switched
on or while driving, and does not go out again, the battery is not
being maintained at the proper power level. Starting reliability may
be impaired. You should have the battery checked by a qualified
workshop as soon as possible.
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Your vehicle and the environment 230Anticipate well in advance
A car uses most fuel when accelerating. If you anticipate hazards
and speed changes well in advance, you will need to brake less and
thus accelerate less. Wherever possible, let the car slow down grad-
ually with a gear engaged, for instance when you can see that the
next traffic lights are red. This takes advantage of the engine
braking effect, reducing wear on the brakes and tyres. Emissions
and fuel consumption will drop to zero due to the overrun fuel cut-
off.
Change gear early to save fuel
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: Shift up to second gear as soon as possible. If
possible, we recommend shifting up to the next gear at approx.
2,000 rpm.
Automatic gearbox: Press the accelerator slowly and avoid using
the “kick-down” feature.
Avoid driving at high speed
Avoid travelling at top speed. Fuel consumption, exhaust emissions
and noise levels all increase very rapidly at higher speeds. Driving at
moderate speeds will help to save fuel.
Do not let the engine idle for longer than necessary
It is worthwhile switching off the engine when waiting in a traffic
jam, at level 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 very long time to warm up when it is running at
idling speed. 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.Regular servicing
Regular servicing can establish a basis for good fuel economy
before you start driving. A well-serviced engine gives you the
benefit of improved fuel efficiency as well as maximum reliability
and an enhanced resale value. A badly tuned engine can consume
up to ten percent more fuel than necessary.
Avoid short trips
The engine and emission control system need to reach their proper
working temperature in order to minimise fuel consumption and
emissions.
A cold engine uses disproportionately more fuel. The engine only
reaches its working temperature after about four kilometres, when
fuel consumption will return to a normal level. This is the reason
why we recommend avoiding short trips wherever possible.
Maintain the correct tyre pressures
Always make sure the tyres are inflated to the correct pressures
⇒page 268 to save fuel. If the tyre pressures are just 0.5 bar too low,
this can increase the fuel consumption by as much as 5 %. Due to
the greater rolling resistance, under-inflation also increases tyre
wear and impairs handling.
Do not use winter tyres all through the year; they will increase fuel
consumption by up to 10 %.
Avoid carrying unnecessary loads
Every kilo of extra weight will increase the fuel consumption, so it is
worth checking the luggage compartment occasionally to make
sure that no unnecessary loads are being transported.
A roof carrier 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 car will
use about 12 % more fuel as a result of the extra wind resistance
caused by the roof carrier - even when it is empty.
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