2008 AUDI S8 sensor

Side airbags
Description of side airbags
The airbag system can provide supplemental protecti on
to properly restrained occupants.
Fi g. 23 6 Sid e a ir b ag
lo ca tio n in the d riv er' s
sea t
The side airbags are located in the sides of the front seat backrests
=> fig. 236 and the rear backrest facing the doors . They are identified
by the word "AIRBAG" .
The side airbag system b asic ally con sist s of :
• the electronic control module and external side impact sensors
• the two side airbags located in the sides of the front backrests
• two rear side airbags
• the a irbag warning light in the instrument cluster.
The airbag system is monitored electronically to make certain that it is functioning properly at all times. Each time you turn on the igni ­
tion, the airbag system indicator light wi ll come o n for a few
seconds (self diagnostics).
The side airbag system supplements the safety belts and can help to reduce the risk of injury to the driver's, front and rear passenger's
upper torso on the side of the vehicle that is struck in a side colli ­
s ion. The airbag deploys only in s ide impacts and on ly when the
vehicle acceleration registered by the control unit is high enough . If
Airb ag syst em
this rate is below the reference value programmed into the control
un it, the side airbags w ill not be triggered, even though the car may
be badly damaged as a result of the col lision. It is not possible to
define an airbag triggering range that wi ll cover every possible
ang le of impact, since the circumstances will vary considerably
between one collision and another. Important factors include, for
examp le, the nature (hard or soft) of the impacting object, the angle
of impact, vehic le speed, etc. =>
page 238, "Important safety instruc ­
tions on the side airbag system".
Aside from their norma l safety function, safety belts work to he lp
keep the driver or front passenger in position in the event of a side
collision so that the side airbags can provide protection .
The airbag system is
not a substitute for your safety belt . Rathe r, it
is part of the overa ll occupant restraint system in your vehicle.
Always remember that the side airbag system can only he lp to
pro tect you if you are wearing your safety belt and wear ing it prop­
erly. This is another reason why you should a lways wear your safety
b elts, n ot just because the law requires you to do so =>
page 209,
"General notes".
I t is important to remember tha t while the supplementa l side airbag
system is designed to reduce the likelihood of serious injuries, other
injuries, for example, swelling, bruising, and minor abrasions can
a lso be associated with deployed side airbags . Remember too, side
airbags will deploy only once and on ly in certain kinds of accidents
-your safety belts are always there to offer pro tec tion .
Vehicle damage, repair costs or even the lack of vehicle damage are not necessarily an indication of over -sensi tive or failed airbag acti ­
vation . In some collisions, both front and side airbags may inflate.
Remember too , that airbags will deploy on ly once and only in
certain kinds of collisions -your safety belts are always there to
offer protection in those acc idents in which airbags are not
supposed to deploy or when they have already dep loyed.
The sid e airbag system will not deploy :
• when the ignition is turned of f
Vehicle care I I Technical data

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• in side collisions when the acceleration measured by the sensor
is too low
• in front -end collisions
• in rear-end collisions
• in rollovers.
In some types of accidents the front airbags, side curtain airbags
and side airbags may be triggered together.
& WARNING
• Safety belts and the airbag system will only provide protection
when occupants are in the proper seating position
~ page 238.
• If the airbag indicator light comes on when the vehicle is being
used , have the system inspected immediately by your authorized
Audi dealer . The airbag may not work properly when the vehicle
acceleration in a side collision is high enough to activate the
airbag .•
How supplemental side airbags work
Side airbags deploy instantly and can help reduce the risk
of upper torso injuries for occupants who are properly
restrained.
Fig . 237 Inflated side
airbags on left side of
vehicle, rear s ide
airbag
When the system is triggered, the airbag is fi lled with propellant gas
and breaks through a seam in the seat surface area marked
"AI RBAG ". I t expands between the side trim panel and the
passenger. In order to he lp provide this additional protection, the
side airbag must inflate within a fraction of a second at very high
speed and with great force . The supplemental side airbag could
injure you if your seating position is not proper or upright or if items
are located in the area where the supplemental side airbag expands.
This applies especially to
children~ page 243, "Ch ild Safety" .
Supplem ental side airbags inflate between the occupant and the
door panel on the side of the vehic le that is struck in certain side
collision~ fig. 237.
Although they are not a soft pi llow, they can "cushion" the impact
and in this way they can he lp to reduce the risk of injury to the upper
part of the body.
A fine dust may develop when the airbag deploys. This is normal
and does not mean there is a fire in the vehicle. •
Important safety instructions on the side
airbag system
Airbags are only supplemental restraints. Always prop­
erly wear safety belts and ride in a proper seating posi­
tion .
There is a lot that you and your passengers must know and act
accordingly to help the safety belts and airbags do their job to
provide supplementa l protection.
& WARNING
An inflating side airbag can cause serious or fatal injury. Improp ­
erly wearing safety belts and improper seating positions increase
the risk of serious personal injury and death whenever a vehicle is
being used .
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& WARNING (continued)
• In order to reduce the risk of injury when the supplemental side
airbag inflates:
-Always sit in an upright position and never lean against the
area where the supplemental side airbag is located.
- Never let a child or anyone else rest their head against the
side trim panel in the area where the supplemental side airbag
inflates.
- Always make sure that safety belts are worn correctly,
- Do not let anyone sitting in the front seat put their hand or any other parts of their body out of the window.
• Always make sure that the side airbag can inflate without inter­
ference.
-Never install seat covers or replacement upholstery over the
front seat backs that have not been specifically approved by
Audi.
- Never use additional seat cushions that cover the areas
where the side airbags deploy .
- Damage to the original seat covers or to the seam in the area
of the side airbag module must always be repaired immedi­
ately by an authorized Audi dealer .
• Objects between you and the airbag can increase the risk of
injury in an accident by interfering with the way the airbag unfolds
or by being pushed into you as the airbag inflates .
- Never place or attach accessories or other objects (such as cup holders, telephone brackets, or even large, bulky objects}
on the doors, over or near the area marked "AIRBAG" on the
seat backrests .
- Such objects and accessories can become dangerous projec­
tiles and cause injury when the supplemental side airbag
deploys.
Controls and equip­ ment Safety first
Vehicle operation
& WARNING (continued)
-Never carry any objects or pets in the deployment space
between them and the airbags or allow children or other
passengers to travel in this position .
• Always use the built -in coat hooks only for lightweight
clothing. Never leave any heavy or sharp-edged objects in the
pockets that may interfere with side airbag deployment and can
cause personal injury in an accident.
• Always prevent the side airbags from being damaged by heavy
objects knocking against or hitting the sides of the seatbacks.
• The airbag system can only be triggered once. If the airbag has
been triggered, the system must be replaced by an authorized
Audi dealership.
• Damage (cracks, deep scratches etc.} to the original seat covers
or to the seam in the area of the side airbag module must always
be repaired immediately by an authorized Audi dealer.
• If children are seated improperly, their risk of injury increases
in the case of an
accident => page 243, "Child Safety".
• Never attempt to modify any components of the airbag system
in any way.
• In a side collision , side airbags will not function properly if
sensors cannot correctly measure increasing air pressure inside
the doors when air escapes through larger, unclosed openings in
the door panel.
-Never drive with interior door trim panels removed.
- Never drive when parts have been removed from the inside
door panel and the openings they leave have not been properly
closed.
- Never drive when loudspeakers in the doors have been
removed unless the speaker holes have been properly closed .
- Always make certain that openings are covered or filled if
additional speakers or other equipment is installed in the
inside door panels .
Vehicle care Do-it-yourself service Technical data

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& WARN ING (c ontinued)
- Alwa ys hav e w ork on the do ors done by an auth ori zed Audi
de ale r or qualified work shop . •
Side curtain airbags (SIDEGUARD™)
Description of SIDEGUARD™ airbags
The SIDEGUARD™ airbag system can provide supple­
mental protection t o properly restrained occupants.
Fig . 23 8 SIDEG UARD ™
s y st em , dri ve r's si de:
s id e c urt a in airb ag
l oca tio n
The side curtain airbags are located on both sides of the interior
above the front and rear side
windows=> fig. 238 . They are identi ­
fied by the word "AIRBAG" on the windshield frame and the center
roof pillar .
The side curtain airbag system supplements the safety belts and can help to reduce the risk of injury for occupan ts' heads and upper
torso on the side of the vehicle that is struck in a s ide collision. The
side curtain airbag inflates only in side impacts and on ly when the
vehic le acceleration registered by the control unit is high enough . If
this rate is below the reference value programmed into the con trol
unit, the side airbags wi ll not be triggered , even though the car may
be badly damaged as a result of the collision . It is not possib le to
define an airbag triggering range that will cover every possible angle of impact, since the circumstances will vary considerab
ly
be tween one collision and another . Important factors include, for
example, the nature (hard or soft) of the impacting object, the ang le
of impact, vehicle speed,
etc .=> page 241 , "How side curtain airbags
work" .
Aside from their normal safety function, safety belts work to help keep the dr iver or front passenger in position in the event of a colli ­
sion so tha t the side curtain airbags can provide protection .
The airbag system is not a substitute for you r safety belt. Rathe r, it
is part of the overa ll occupant restrain t system in your vehicle .
A lways remember that the airbag system can only help to protect
you if you are wearing your safety belt and wearing it properly. This
is another reason why you should always wear your safety belts, not
just because the law requires you to do
so => page 209, "General
notes".
I t is important to remember that while the side curtain airbag
system is designed to he lp reduce the like lihood of serious injuries,
other injuries, for examp le, swelling, bruising, and minor abrasions
can a lso be associated with these airbags. Remember too, these
airbags will deploy only once and only in certain kinds of accidents
-your safety belts are a lways there to offer protection.
The side curta in airbag system ba sically con sist s of:
• The electronic control module and externa l side impact sensors
• The side curtain airbags above the front and rear side windows
• T he airbag indicator light in the instrument panel
The airbag system is mo nitored elec tronica lly to make certain it is
functioning proper ly at all times . Each time you turn on the ignition,
the airbag system indicator light wi ll come on for a few seconds
(self diagnostics).
T he sid e curtain airbag i s not act ivated:
• if the ignition is turned off,
• in side collisions when the acce leration measured by the sensor
is too low ,
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11111 Child Safety
------!....------------------------------
&, W ARNING (continued )
• Alway s inst all rear-facing child safety seats on the rear seat .
• If you mu st in sta ll a rear ward f acing child safet y seat on the
front pa ssenger seat in exceptional circum stan ces and the
PASSENGER AIR BAG OFF light doe s not come on and stay on,
immediately inst all the rear-facing child safety seat in a rear
s eating po sition and ha ve the airbag sy stem inspe cted immedi ­
atel y by your Audi de aler .
& WARNING
If, in exceptional circumstance s, you mu st in stall a forward -facing
c hild re straint o n the fr ont p assenger 's seat:
• Alway s make sure the forward -fa cing s eat ha s been de signed
a nd cert ified by it s m anufa cturer for use on a front seat w ith a
pa ssenger front and side airbag.
• Always follow the manufacturer's instruct ions provided with
the child safety seat or carrier.
• Alway s move the pa ssenger seat into it s re armost position in
the seat' s fore and aft adju stment range , as far aw ay from the
ai rbag as possibl e befo re installing the ch ild restr aint . The ba ck­
rest mu st be adjusted to an upright po sition.
• Alway s m ake sure that the PASSENGER AIR BAG OFF l ight
c ome s on and stays on all the time whenever the ignition is
sw it c hed on . •
Advanced front airbag system and children
Your vehicle is equipped with an "Advanced Airbag System" in
compl iance with U nited States Federa l Motor Vehicle Safety Stan­
dard { FMVSSl 208 as applicable at the time your vehicle was manu ­
factured. T
he Advanced Airbag system in your vehicle has been certified to
meet the " low -risk" requirements for 3 and 6 year -old chi ldre n on
the passenger side and smal l adults on the driver side . The low risk
deployment criteria are intended to reduce the risk of injury through
interaction with the airbag that can occur, for example, by being too
close to the steering wheel and instrument panel when the airbag
inflates. In addition, the system has been certified to comply with
the "suppression" requirements of the Safety Standard, to turn off
the front airbag for infants up to 12 months who are restra ined on
the front passenger seat in child restraints that are listed in the
Standard.
Even though your vehic le is equipped with an Advanced Airbag
system, al l ch ildren, especially those 12 years and you nger, should
a lways ride in the back seat properly restrained for their age and
size . The airbag on the passenger side makes the front seat a poten­
tia lly dangerous p lace for a ch ild to ride. The front seat is not the
safest p lace for a child in a forward -facing child safety seat . It can be
a very dangerous p lace for an infant or a larger ch ild in a rearward ­
facing seat. •
Advanced Airbags and the weight-sensing
mat in the front seat
The Advanced Airbag Sys tem in your vehicle detects the presence
of an infant or child in a chi ld restra int on the front passenger seat
using the weight -sensing mat in the seat cushion and the sensor
below the safety belt latch on the front passenger seat that measures the tension on the safety belt.
T he weigh t-sensing mat measures total weight o f the chi ld and the
child safety seat and a child blanket on the front passenger seat . T he
weig ht o n the fr ont passenger seat is rela ted to the desig n of the
chi ld restraint and its "footprint", the size and shape of the bottom
of the child restraint as it sits on the seat . The weight of a child
restraint and its "footprint" vary for different kinds of child
~

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restraints and for the different models of the same kind of child
restraint offered by child restraint manufacturers .
The weight ranges for the individual types , makes and mode ls of
child restraints that the NHTSA has specified in the Safety Standard
together with the weight ranges of typ ical infants and typica l 1 year­
old child have been stored in the control unit of the Advanced
Airbag System. When a ch ild restra int is being used on the front
passenger sea t wi th a typical 1 y ear-old child, the Advanced Airbag
System compares the weight measured by the weight sensing mat
with the information stored in the e lectronic control unit .
The electronic contro l unit also registers the tension on the front
passenger safety be lt . The tens ion on the safety belt for the front
passenger seat will be different for an adult who is properly using
the safety belt as compared to the tension on the belt when it is used to attach a chi ld restraint to the seat. The sensor below the
latch for the safety belt for the front seat passenger measures the
t e nsion on th e be lt . The input from this sensor is then used with the
weight to "decide" , w hether there is a child restraint with a typical 1
year-o ld child on the front passenger seat and whether or not the
airbag must be turned off .•
Child restraints and Advanced Airbags
Regard less of the child restraint that you use, make sure that i t has
been certified to meet United States Federa l Motor Vehic le Safety
Standards and has been certified by its manufacturer for use with
an airbag . Always be sure that the chi ld restraint is properly
insta lled at one of the rear seating positions . If in exceptiona l
circumstances you must use it on the front passenger seat, carefully
read all of the information on child safety and Advanced Airbags
and heed a ll of the app licable WARNINGS. Make certain that the
child restraint is correct ly recognized by the weight -sensing mat
inside the front passenger seat, that the front passenger airbag is
turned off and that the airbag status is always correct ly signa led by
t he
P ASS ENGER AIR B AG OFF light .
Controls and equip­
ment Safety first Vehicle operation
Many types and mode
ls of chi ld restraints have been available over
t he years, new mode ls are introduced regular ly incorpora ting new
and improved designs and older models are taken out of produc­
tion. Child rest raints are not standardized . Child restraints of the
same type typically have different weights and sizes and different
'footprints,' the size and shape of the bottom of the chi ld restra int
that sits on the seat, when they are insta lled on a veh ic le seat. These
differences make it virtua lly impossible to certify comp liance with
the requirements for advanced airbags with each and every child restraint that has ever b een sold in th e past or will b e sold over the
course of the usefu l life of your veh ic le .
For this reason, the Uni ted S tates National Highway Traffic Safety
Admin istration has pub lished a lis t of spec ific type, makes and
models of child restra ints that must be used to cert ify compl iance
of the Advanced Airbag System in your vehicle with the suppression
requ irements of Federa l Motor Veh ic le Safety Standard 208. These
child restraints are:
A. Ca r beds, man ufac tured on or afte r Sept ember 1 ,
20 0 4:
• Cosco Dream R ide 02-719
B . Rea r fa cin g c hild re straint syste ms, manu factured
o n or aft er Se ptemb er 1 , 20 04:
(When the restraint system comes equipped with a removab le base,
compliance has to be certified with or without the base) .
• Britax Handle with Care 191
• Century Assura 4553
• Century Smart F it 4543
• Cosco Arriva 02727
• E venflo Discovery Adjust R ig ht 212
• Evenflo First Choice 204
• Graco lnfant8457
Vehicle care Do-it-yourself service Technical data

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Intelligent technology
Notice about data recorded by
vehicle control modules
Your vehicle is not equipped with an Event Data Recorder (EDRl,
installed by some manufacturers for the express purpose of
capturing data for retrieval after an accident or crash event . EDR's
are sometimes called "crash recorders".
Some state laws restrict the retrieva l or downloading of data stored
by EDR's that were insta lled in a vehicle for the express purpose of
retrieving data after an accident or cras h event without the owner's
consent.
Although your vehicle is not equipped with an EDR, it is equipped
with a number of electronic control modules for various vehicle systems such as, for example, engine function, emission contro l, as
we ll
as for the a irbags and safety belts.
These electronic control modules also record vehic le-related data
dur ing norma l ve hicle opera tion for diagnost ic and repair purposes .
The recording capacity of the electronic control modules is limited
t o data (no sound is recorded) and only a small amount of data is
actua lly recorded over a very limited period of time and stored when
a system fault or other condition is sensed by a control unit. Some
of the data then stored may relate to vehic le speed, d irection,
braking as we ll as restraint system use and performance in the
event of a crash o r other condition . Stored data can only be read and
downloaded with special equipment. •
Electronic Stabilization Program (ESP)
General information
The ESP improves the vehicle stability.
I~
" "'
( ~ 1~ IA I 3-)
Fi g. 25 4 Cen ter
co nso le w it h ES P
sw itch
ESP is designed to he lp you maintain vehic le control in situations
where the car approaches the limits of "grip", especia lly when
acce lerating and cornering . ESP reduces the risk of skidding and
improves stabil ity under al l road conditions.
T he system operates across the entire speed range in combination
with the ABS system. If the Ant i-Lock Brake System (ABS) malfunc­
tions, the ESP wi ll also shut down .
How the syste m w ork s
The Anti -Lock Brake System (ABS), Electronic Differential Lock (EDU
and the Anti-Sl ip Regulation System (ASR) are integrated in the e lec­
tronic stabi lization program. In addition to the data provided by
t hese functions, the ESP control unit requires additional measure ­
ment data provided by high performance sensors . The rotational
speed of the veh ic le about its vertica l axis, the lateral acce lerat ion
acting on the vehicle, the brake pressure and the steering angle are
a ll measured . _,,,,

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Overheating of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads, the EDL cuts out temporarily . The
vehicle remains operational and behaves in the same way as a
vehicle without EDL.
As soon as the brake has cooled down, EDL switches on again auto ­
matically.
& WARNING
• When accelerating on slippery surfaces, such as on ice or snow,
always be careful when depressing the accelerator pedal. Even
with the EDL working, the drive wheels can spin and reduce your ability to control your car. Risk of crash!
• The increased safety afforded by
EDL does not mean that you
can take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
If a fault occurs in the ABS, the EDL is also not functioning. This is
indicated by the ABS warning
light => page 21. •
Anti-Slip Regulation System (ASR)
The Anti-Slip Regulation System prevents the driven
wheels from spinning when the car is accelerating.
General notes
The Anti-Slip Regulation System (ASR) is integrated in the electronic
stabili zation program (ESP) . When the vehicle starts up and acceler­
ates, the wheels are prevented from spinning by adjusting the
engine power to match the amount of grip available from the road
surface.
How the system works
ASR performs automatically, i.e. without the driver's intervention.
With the aid of the ABS
sensors=> page 272, ASR monitors the
speed of the driven wheels. If the wheels start to spin, the engine
power is reduced automatically until the tires find enough grip to
lock onto the road surface . The system is active across the entire
speed range.
The ASR works in conjunction with the ABS. If a malfunction should
occur in the ABS, the ASR will also be out of action.
& WARNING
The increased safety afforded by ASR does not mean that you can
take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
To ensure that the ASR works properly, all four wheels must be fitted
with identical tires Any differences in rolling radius of the tires can
cause the system to reduce engine power when this is not desired.
See
also=> page 336, "New tires and replacing tires and wheels ".•
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The brakes on today's automobiles are still subject to wear,
depending largely on operating conditions and driving
habits=:,& .
On vehicles which are driven mostly in stop-and-go city traffic or
which are driven hard, the brake pads should be checked by your
authorized Audi dealer more often than specified in the
Warranty &
Maintenance booklet. _,,,