belt AUDI S8 2009 Service Manual

___ A_ ir_b _a_ g;:::;_ s--:.. y_s _t _e _m _________________________________________________ _
& WARNING
Changing the vehicle's su spension includ ing use of un approved
tire -rim combinations can change Advanced Airbag performance
and increase the ris k of serious personal injury in a crash .
• Never install suspen sion component s that do not have the
same performance chara cteristics as the components or iginally
installed on your vehicle.
• Never use tire-r im comb inations that have not been approved
by Audi.
& WARNING
Items stored between the safety belt bu ckle and the center
c onsole can cause the sensors in the buc kle to send the wrong
information to the electroni c control module and prevent the
Advanced Airbag System from working properly .
• Alway s make sure that nothing can interfere with the safety
belt buckles and that they are not obstructed .
<£> For the sake of the environment
Undeployed airbag modules a nd pretensioners might be classified
as Pe rchlorate Mat erial -spe cia l han dling may a pply, see
www.dtsc.ca.gov/hazardouswaste/perchlorate. When the vehicle or
par ts o f the restraint syst em i ncludi ng ai rbag modules and saf ety
belts with pretensioners are scrapped, a ll app licab le laws and regu­
latio ns must be observed . Yo ur au thori zed A udi dealer is fam ilia r
with these requirements and we recommend that you have your
dealer perfo rm this serv ice for you .•
Knee airbags
Description of knee airbags
T he airba g sys tem c an prov id e sup plemen tal prot ect ion
t o pro pe rly rest rained fron t seat occ upant s.
0
Fig. 2 36 Drive r's
airba g
The airbag for the driver is located in the instrument panel under ­
neath the steering wheel=> fig. 236, the airbag for the passenger is
at about the same height in the instrument panel und erneath the
glove compartment.
T he knee air bag offe rs addi tio nal pr ote cti on to the d river's a nd
passenger 's knees and upper and lower thigh ar eas as a supple ­
me nt to t he sa fety be lts.
I f the front airbags deploy , the knee airbags also deploy in frontal
collisions above a certain severity=> page
229, "M ore important
thi ngs to kno w about fron t a irba gs" .
B esides their normal safety function, safety belts wor k to help keep
t h e dri ver o r fr on t passeng er in pos itio n in case of a fro ntal col lis ion
so that the airbags can provide protection .
T he airbag system is not a substitute for your safety belt . Rathe r, it
i s part of the overa ll occupa nt res tra int system i n your ve hi cle.
A lwa ys re member that the airbag system can on ly help to protect
you if you a re wearing your safe ty belt and weari ng it properly . T hi s .,,_

is why you should always wear your safety belt, not just because the
l a w requ ire s you to do so =>
page 211, "Genera l notes" .
The safety belt buckle for the driver and front seat passenger have switches that tell the airbag control module if the safety belt is
being used or not. If the safety belt is being used , the knee airbag
will deploy at a s lightly higher rate of deceleration than if the belt is
not be ing used . Therefore, in a par ticular collision, it is possib le that
an airbag will not deploy a t a seating position where the safety belt
is be ing used but will inflate at the position where the safety belt is
not being used .
Remember too, airbags will deploy only once and only in ce rtain
kinds o f accidents - your safety be lts are always there to offer
protection in those accidents in wh ich airbags are not supposed to
deploy or when they have already deployed, for examp le when you r
vehicle strikes or is struck by another after the first collision.
T his is just one of the reasons why an ai rbag is not a substitute for
the safety be lt. The airbag system works most effectively when used
with the safety belts . Therefore, a lways wear your safety belts
correctly.
I t is important to remember that while the supplemental airbag
system is designed to reduce the like lihood of ser ious injuries, o ther
injuries, for example, swelling, bruising, and minor abrasions can
a lso be associated with airbags.
The kn ee airbag s ystem bas ically con sists of:
• The electronic control module
• Two inflatable airbags (ai rbag and gas generato r), one for the
driver and one for the front passenger
• T he airbag indicator light in the instrument panel
The kn ee airbag system w ill not deploy :
• whe n the ignit ion is turned off
• in front -end collisions when the deceleration measured by the
control uni t is too low
• in side collisions
Safety first
Airb ag sy ste m
• in rear -end co llisions
• in ro llovers
• in the event of a system malfunction (warning/indicator light illu ­
minated)=>
page 19 .
& WARNING
• Safety belt s and the airbag sy stem ca n only p rov ide protec tion
when o ccupants are in the proper seating po sition
=> page 229 .
• If the airbag indi cator light come s when the vehi cle is b eing
u sed , have the system in spected immediately by your authori zed
Audi deale r. Th e airbag may no t work prope rly when the vehicle
acceleration in a side colli sion is high enough to deploy the airbag.
See also =>
page 19. •
How knee airbags work
The risk of injury to the leg are a i s reduce d by fully
depl oyed knee airb ags .
Fig . 237 In fl ate d
ai rba gs prot ecting in a
frontal colli sio n
The knee airbag system has been designed so that the airbags for
the drive r and front passenger a re depl oyed in certain but not all
frontal col lisions.
ai,.
Vehicle care I I irechnical data

1111 Airbag system
----==---=--------------------------------
If the front airbags deploy, the knee airbags also dep loy in frontal
c ollis ions ab ove a cer tai n se ver ity.
When the system is deployed, the airbags start to f ill with a prope l­
lant gas, and inf late between the lower part of the instrument pane l
and t he dr ive r and the lowe r pa rt o f the instrument pane l and t he
front passenger ~ page
229 , fig. 23 4.
Althoug h they are no t a so ft pi llow, t hey can "cushion" th e impac t
and in this way they can he lp to reduce the risk of injury to the lower
e xtr em it ies .
A ll t his takes p lace instantaneously, so fast t hat many people do n't
even realize that the ai rbags have deployed. The airbags a lso inflate
w it h a great deal o f force and it is impor tant for occupan t sa fety t hat
nothing shou ld be in their way when they dep loy.
F u lly infla ted ai rbags i n co mb ination with p roperly worn safety be lts
s low down and limit the occupant's forward movement and he lp to
r ed uce the ris k.•
Important safety instructions on the knee
airbag system
A irb ags ar e onl y supplemen tal r es tra in ts. Alw ays wea r
s af ety be lts cor re ctly and r ide i n a prop er seatin g position.
There is a lo t tha t you a nd your passengers must know a nd do to
help the safet y be lts and airbags to provide supp lemental protec ­
ti on .
& WARNING
An inflating knee airbag can cause serious injury. Wearing safety
belts incorrectly and improper seating positions increase the risk
of serious personal injury and death whenever a vehicle is being
used .
• The airbag system cannot protect you properly if you are
seated too clo se to any of the airbag locations. When adjusting
& WARNING (continued)
their seat positions , it is important that both the driver and the
front passenger keep their upper bodies and knees at the
follow ing min imum safe distances :
- 1 O inches (25 cm) between the chest and the steering
wheel /instrument panel .
- 4 inches (10 cm) between the knees and the lower part of the instrument panel.
• The risk of personal injury increases if you lean forward or to
the side, or if the seat is improperly positioned and you are not
wearing your safety belt. The r isk increases even more should the
airbag deploy .
• Always make sure that the knee airbag can inflate without
interference . Objects between yourself and the airbag can
increase the risk of injury in an accident by interfering w ith the
way the airbag deploys or by being pushed into you as the a irbag
deploys.
-No persons (children) or animals should ride in the footwell
in front of the passenger seat . If the airbag deploys , this can
result in serious or fatal injuries .
- No objects of any kind should be carried in the footwell area
in front of the driver's or passenger's seat. Bulky objects (shop­
ping bags , for example) can hamper or prevent proper deploy ­
ment of the airb ag. Sm all objects can be thrown through the
vehicle if the airbag deploys and injure you or your passengers .
• Make sure there are no cracks , deep scratches or other damage
in the area of the instrument panel where the knee airbags are
located .
• If children are incorrectly seated , their risk of injury increases in
the case of an accident
~ page 245 , "Child Safety". •

Side airbags
Description of side airbags
The airbag system can provide supplemental protecti on
to properly rest rained occupants.
Fi g. 238 Si de a ir b ag
lo ca tio n in th e driv er's
seat
The side airbags are located in the sides of the front seat backrests
=> fig. 238 and the rear backrest facing the doors . They are identified
by the word "AIRBAG" .
The sid e ai rbag sy stem b asica lly consis ts of :
• t he electronic control module and external side impact sen sors
• 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 on 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 ­
sion. The airbag deploys only in side impacts and on ly when the
vehicle acceleration registered by the control unit is high enough . If
Safety first
Airb ag sy ste m
this rate is below the reference value programmed into the control
unit, 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, vehicle speed, etc.=>
page 240, "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 even t 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 overall 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 always wear your safety
belts, not just because the law requires you to do so==>
page 211,
"General notes" .
I t is important to remember that 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 s ide airbags . Remember too, side
airbags will deploy only once and only 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 -sensitive 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 w ill not deploy :
• when the igni tion is turned of f
•
Vehicle care I I irechnical data

___ A_ ir_b _a_ g;:::;_ s--:.. y_s _t _e _m _________________________________________________ _
• 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 240.
• 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. 239 Inflated side
airbags on left side of
vehicle, rear s ide
airbag
When the system is triggered, the airbag is filled with propellant gas
and breaks through a seam in the seat surface area marked
"AIRBAG" . It 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 245, "Child 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. 239.
Although they are not a soft pillow, 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 . _.,

_______________________________________________ .=_A ::_ i :.:.r ~b ~a:=.; 9!:!...: S~ y[: s~ t~ e:::_ m ~ ----
& 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.I 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 245, "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

___ A_ ir_b _a_ g;:::;_ s--=- y_s _t _e _m _________________________________________________ _
& WARNING (c ont in ued)
- Alwa ys ha ve work on th e doo rs done by an auth ori ze d Aud i
d ea le r or q ualified works hop . •
Side curtain airbags
Description of side curtain airbags
The side curtain airbag system can provide supplemental
protection to pr operly restrained occupants .
Fig. 240 Side cu rtai n
ai rb ags, drive r's side:
s ide c urt a in airb ag
l oca tion
The side curtain airbags are located on both sides of the interior
above the front and rear side windows~ fig. 240. 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 occupants' heads and upper
torso on the side of the vehicle that is struck in a side 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
t his rate is below the re ference value programmed into the control
unit, the side airbags will 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 considerably
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 243, "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 that the side curtain airbags can prov ide protection .
The airbag system is not a substitute for your safety belt. Rathe r, it
is part of the overall occupant restraint system in your vehicle .
A lways remember that the airbag system can on ly 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 211, "General
notes".
It 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 example, swelling, bruising, and minor abrasions
can a lso be associated with these airbags upon deployment.
Remember too, these airbags wi ll dep loy only once and only in
certain kinds of accidents -your safety belts are always there to
offer protection.
Th e s ide cu rtai n air ba g sys te m b asi ca lly co nsis ts of:
• The electronic control modu le and external side impact sensors
• T he side curtain airbags above the front and rear side windows
• The airbag indicator light in the instrument panel
The airbag system is monitored electronically to make certain it is
funct ion ing proper ly at all times . Each time you turn on the ignition,
the airbag system indicator light will come on for a few seconds (self diagnostics).
The s ide c urtain a irbag is no t activa te d:
• if the ignition is tu rned off,

• in side collisions when the acceleration measured by the sensor
is too low,
• in front -end collisions,
• in rear-end collisions,
• in rollovers.
& WARNING
• Safety belts and the airbag system will only provide protection
when occupants are in the proper seating position
=> page 86,
"General recommendations" .
• If the airbag indicator light comes on when the vehicle is being
used, have the system inspected immediately by your authorized
Audi dealer . The side curtain airbag may not work properly even
when the vehicle acceleration in a side collision is high enough to
activate the airbag.
c:J
How s ide curtain airbags work
Side curtain airbags can work together with side airbags
to help reduce the risk of head and upper torso injuries for
occupants who are properly restrained.
Safety first
Fig. 241 Illustration o f
prin ciple: Inflated side
c urtain airbags on the
left side
Airbag system
The side curtain airbags inflate between the occupant and the
windows on the side of the vehicle that is struck in a side collision
=> fig. 241 .
When the system is triggered, the side curtain airbag is filled with
propellant gas and breaks through a seam above the front and rear
side windows identified by the AIRBAG label. In order to help
provide this additional protection, the side curtain airbag must
inf late within the blink of an eye at very high speed and with great
f orce . The side curtain airbag could injure you if your seating posi­
tion is not proper or upright or if items are located in the area where
the supplementa l side curtain airbag inflates . This applies espe ­
cially to children=>
page 245.
Although they are not a soft pil low, side curtain airbags can
"cushion" the impact and in this way they can help to reduce the risk
of injury to the head and the upper part of the body.
A fine dust may develop when the airbag deploys. This is quite
normal and does not mean there is a fire in the vehic le .•
Important safety instructions on the side
curtain 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 do to
help the safety belts and airbags do the ir job to provide supple­
mental protection.
& WARNING
Improperly wearing safety belts and improper seating positions
increase the risk of serious personal injury and death whenever a
vehicle is being used. •
Vehicle care I I irechnical data