belt AUDI A4 AVANT 2008 Service Manual

Airbag system 111111
-----------------------------=--=-------
It is important to remember that while the supplemental airbag
system is designed to reduce the likelihood of serious injuries, other
injuries, for example swelling, bruising and minor abrasions, can
also happen when airbags inflate. Airbags do not protect the arms
or the lower parts of the body. Front airbags only supplement the
three point safety belts in some frontal collisions in which the
vehicle deceleration is high enough to deploy the airbags.
Front airbags
will not deploy:
• if the ignition is switched off when a crash occurs,
• in side collisions,
• in rear -end collisions,
• in rollovers ,
• when the crash deceleration measured by the airbag system is
less than the minimum threshold needed for airbag deployment as
registered by the electronic control unit.
The front passenger airbag
will also not deploy:
• when the front passenger seat is not occupied,
• when the weight on the front passenger seat as sensed by the
Advanced Airbag System indicates that the front airbag on the
passenger side has to be turned off by the electronic control unit
(the PASSENGER AIR BAG OFF light comes on and stays onl.
& WARNING
Sitting in the wrong position can increase the risk of serious injury
in crashes.
• To reduce the risk of injury when the airbags inflate, the driver
and passengers must always sit in an upright position, must not
lean against or place any part of their body too close to the area
where the airbags are located.
• Occupants who are unbelted, out of position or too close to the
airbag can be seriously injured by an airbag as it unfolds with
great force in the blink of an
eye :::::, page 189.
Controls and equip­ ment Safety first
Vehicle operation
& WARNING
A child in a rearward-facing child safety seat installed on the front
passenger seat will be seriously injured and can be killed if the
front airbag inflates
-even with an Advanced Airbag System.
• The inflating airbag will hit the child safety seat or infant
carrier with great force and will smash the child safety seat and
child against the backrest, center arm rest, door or roof.
• Always install rear-facing child safety seats on the rear seat.
• If you must install a rearward facing child safety seat on the
front passenger seat because of exceptional circumstances and
the PASSENGER AIR BAG OFF light does not come on and stay on, immediately install the rear-facing child safety seat in a rear
seating position and have the airbag system inspected by your
Audi dealer .
& WARNING
Objects between you and the airbag will increase the risk of injury
in a crash by interfering with the way the airbag unfolds or by
being pushed into you as the airbag inflates .
• Never hold things in your hands or on your lap when the vehicle
is in use.
• Never transport items on or in the area of the front passenger
seat. Objects could move into the area of the front airbags during
braking or other sudden maneuver and become dangerous projec ­
tiles that can cause serious personal injury if the airbags inflate.
• Never place or attach accessories or other objects (such as cup
holders, telephone brackets, large, heavy or bulky objects) on the
doors, over or near the area marked "AIRBAG" on the steering
wheel, instrument panel, seat backrests or between those areas
and yourself. These objects could cause injury in a crash, espe­
cially when the airbags inflate.
• Never recline the front passenger's seat to transport objects.
Items can also move into the area of the side airbag or the front _,,
Vehicle care Do-it-yourself service Technical data

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PASSENGER AIR BAG OFF light
N
-M -J., a, cc
Fi g. 18 0 Sec tion fr om
t h e i nstr um ent pa nel:
P ASSE NG ER AI R BA G
OFF lig ht
The PASSENGER AIR BAG OFF light is located in the center o f the
ins trumen t panel
=> fig . 180 .
The PASSENGER AIR BAG OFF light wil l come on and stay on to te ll
you when the front Advanced Airbag on the passenger side has been turned off by the electronic control unit. Each time you turn on
the ign it ion, the
PA SS ENGER AIR BA G OFF light wi ll fl as h for a few
seconds and :
• will stay on if t he front passenger seat is not occupied,
• will stay on if there is a small child or chi ld restraint on the front
passenger seat,
• will go out if the front passenger seat is occupied by an adult as
registered by the we ight -sens ing mat.
The
PA SS ENGER AIR B AG OFF light mu st come on and stay on if the
ignition is on and
• a car bed has been instal led on the front seat, or
• a rearward -facing chi ld restraint has been installed on the front
passengerseat,or
Controls and equip­ ment Safety first
Vehicle operation
• a forward -facing child restraint has been instal led on the front
passenger seat, or
• the weight register ed on the front passenger seat is equa l to or
less than the combined weigh t of a typica l 1 year-old restrained in
one of the rear -facing or forward -facing infant restraints listed in
Federa l Motor Veh ic le Safe ty S tandard
208 with wh ich the Advanced
Airbag System in your vehicle was certified .
If the front passenger seat is not occupied, the front airbag will not
dep loy, and the
PA SS ENGER AIR BAG OFF light will stay on . Never
insta ll a rearward -facing child restraint on the front passenger seat,
the safest place for a child in any kind of ch ild restraint is at one of
the seating positions on the rear
seat => page 189, "Ch ild restraints
on the front sea t-some important things to know"
and => page 210,
"Chi ld Safety" .
If the PASSENGER AIR BAG OFF light comes on when one of the
condit ions listed above is met , be sure to check the light regu lar ly
to make certain that the
PA SSENGER AIR BAG OFF light stays on
cont inuously whenever the ignition is on . If the PASSENGER AIR
BAG OFF light does not appear and not stay on all the time , stop as
soon as it is safe to do so and
• reactivate the system by turning the ignition off and then turning
it on again;
• remove and reinstall the ch ild restraint. Make sure that the child
res tra int is proper ly instal led and t hat t he sa fety be lt for the front
passenger seat has been correctly routed around the child restraint
as described in the chi ld restraint manufacturer's instructions;
• make sure that the convertible locking feature on the safety belt
for the front passenger seat has been activated a nd that the safety
belt has been pulled t ight . The belt must not be loose or have loops
of slack so t hat t he sensor below t he safety belt latch on the seat can
do its job
=> page 220.
• make s ure that th ings that may inc rease the we ight of the child
and child safety seat are not being transported on the front
passenger seat;
Vehicle care Do-it-yourself service Technical data

__ .....;.A..;.;.;. ir.;;b ;..; a;;;. g=.... s;;;..!. y.;;s ;.;;t ..;;e ;.;.m.;..;... ________________________________________________ _
• make sure that the safety belt tension sensor is not blocked.
Shake the safety belt latch on the front passenger seat back and
forth;
• If a strap or tether is being used to tie the child safety seat to the
front passenger seat, make sure that it is not so tight that it causes
the weight -sensing mat to measure more weight than is actually on
the seat.
If the PASSENGER AIR BAG OFF light still does not come on and does
not stay on continuously (when the ignition is switched on),
• take the child restraint off the front passenger seat and install it
properly at one of the rear seat positions. Have the airbag system
inspec ted by your Audi dealer immediately .
• move the child to a rear seat position and make sure that the
child is properly restrained in a child restraint that is appropriate for
its size and age.
The
PASSENGER AIR BAG OFF light should NOT come on when the
ignition is on and an adult is sitting in a proper seating position on
the front passenger seat. If the
PASSENGER AIR BAG OFF light
comes on and stays on or flashes for about 5 seconds while driving,
under these circumstances, make sure that:
• the adult on the front passenger seat is properly seated on the
center of the seat cushion with his or her back up against the back ­
rest and the backrest is not
reclined~ page 168, "Proper occupant
seating positions",
• the adult is not taking weight off the seat by holding on to the
passenger assist handle above the front passenger door or
supporting their weight on the armrest,
• the safety belt is being properly worn and that there is not a lot
of slack in the safety belt webbing,
• accessory seat covers or cushions or other things that may cause
an incorrect reading or impression on the weight-sensing mat
under the upholstery of the seat have been removed from the front
passenger seat, •
a safety belt extender has not been left in the safety belt latch for
the front passenger seat.
In addition to the
PASSENGER AIR BAG OFF light in the center of the
instrument panel, the message
PASSENGER AIR BAG OFF or
PASSENGER AIR BAG ON will briefly appear in the instrument cluster
display. This is to inform the driver of the current front passenger
airbag status. •
Important safety instructions on monitoring
the Advanced Airbag System
& WARNING
An airbag system that is not functioning properly cannot provide
supplemental protection in a frontal crash.
• If the airbag indicator light comes on, it means that there may
be something wrong with the Advanced Airbag System. It is
possible that the airbag will inflate when it is not supposed to, or
will not inflate when it should.
• Have the airbag system inspected immediately by your Audi
dealer.
& WARNING
If the front airbag inflates, a child without a child restraint, in a
rearward-facing child safety seat or
in a forward-facing child
restraint that has not been properly installed will be seriously
injured and can be killed .
• Even though your vehicle is equipped with an Advanced Airbag
System, make certain that all children, especially 12 years and
younger, always ride on the back seat properly restrained for their age and size .
• Always install forward or rear-facing child safety seats on the
rear seat -even with an Advanced Airbag System.
.,_

-Airbag system ---=--.:..,.._ _________________________________ _
&, WARNING (continued )
cellular telephones and CB radios, etc .) must be performed by a
qualified technician who has the training and special equipment
necessary .
• For any work on the airbag system , we strongly recommend
that you see your authorized Audi dealer or qualified workshop .
• Never modify the front bumper or parts of the vehicle body .
• Always make sure that the side airbag can inflate without inter ­
ference :
- Never install seat covers or replacement upholstery over the
front seatba cks that have not been specifically approved by
Audi.
- Never use additional seat cushions that cover the areas
where the side airbags inflate.
- 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 .
• The airbag system can be activated only once. After an airbag
has inflated , it must be replaced by an authorized Audi dealer or
qualified technician who has the technical information , training
and special equipment necessary.
• The airbag system can be deployed only once. After an airbag
has been deployed, it must be replaced with new replacement
parts designed and approved especially for your Audi model
version. Replacement of complete airbag systems or airbag
components must be performed by qualified workshops only .
Make sure that any a irbag service action is entered in your Audi
Maintenance
& Warranty booklet under AIRBAG REPLACEMENT
RECORD .
• In accidents when an airbag is deployed, the vehicle battery
separates the alternator and the starter from the vehi cle electrical
system for safety reasons with a pyrotechnic circuit interrupter.
-Work on the pyrotechni c circuit interrupter must only be
performed by a qualified dealer -risk of an accident !
&, WARNING (continued )
-If the vehicle or the circuit interrupter is scrapped, all appli­
cable safety precautions must be followed.
•
Other things that can affect Advanced Airbag performance
Changing the vehic le 's suspension system can change the way that
t he A dvance d Ai rbag S ystem p erf o rm s in a c rash. F or example,
using tire -rim combinations not approved by Audi, lowerin g the
ve hicle , ch ang ing the stiff ness of the suspe nsion, includ ing the
springs, suspension struts, shock absorbers etc. can chang e the
fo rces that a re measured by the airbag senso rs and se nt to the elec­
tronic control u nit. Some suspension chan ges can, for exampl e,
i n crease the fo rce level s measured by the sen so rs and ma ke the
a irbag s yste m de plo y in cras he s in w hi ch it wou ld not de ploy if th e
changes had not been made. Other kinds of changes may reduce
t h e fo rce lev els measu red by the senso rs a nd p reven t the airb ag
from dep loying when it should.
T he sens ors i n the safe ty belt buckle f or the dri ve r and front
passeng er seat tell t he electronic contro l modu le if the safety belt is
la tched o r not. If t he sa fe ty bel t i s being used, the fro nt ai rbag wi ll
deploy at a s ligh tly high er rate o f veh icle dece lerat io n th an if th e
safety be lt is not being u sed . Th erefo re , in a particula r co llision, it is
poss ib le th at a n airbag will not deplo y at a seat ing po sit io n wh ere
the safety be lt is being used but wi ll inflate at the pos ition where the
safety be lt is not bei ng used . It is im po rta nt tha t noth ing i nte rfere
with the safety belt buc kles so that the sensors can send the correct
i nf orm atio n abou t s afe ty belt use to th e electr onic co ntrol uni t.
~

& WARNING
Changing the vehicle's suspension including use of unapproved
tire-rim combinations can change Advanced Airbag performance and increase the risk of serious personal injury in a crash.
• Never install suspension components that do not have the
same performance characteristics as the components originally
installed on your vehicle.
• Never use tire-rim combinations that have not been approved
by Audi.
& WARNING
Items stored between the safety belt buckle and the center
console can cause the sensors in the buckle to send the wrong
information to the electronic control module and prevent the
Advanced Airbag System from working properly .
• Always make sure that nothing can interfere with the safety
belt buckles and that they are not obstructed . •
Safety first
Airbag system
Side airbags
Description of side airbags
The airbag system can provide supplemental protection
to properly restrained occupants.
Fig. 181 Side airbag
location in the driver's
seat
The side airbags are located in the sides of the front seat backrests
=> fig. 181 and the rear backrest* facing the doors. They are identi­
fied by the word "AIRBAG".
The side airbag system basically consists 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 (as an ordered
option)
• the airbag warning light in the instrument cluster .
Th e 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 will 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*
.,_
irechnical data

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passenger's upper torso on the side of the vehicle that is struck in a
side co llis ion. The airbag dep loys on ly in side impacts and only
when the vehic le acce leration registered by the control unit is high
enoug h. If this rate is below the reference va lue programmed into
the control unit, the side airbags will not be triggered, even though
the car may be badly damaged as a resu lt of the collision . It is not
possible to define an airbag trigger ing range that wi ll cover every
possible angle of impact, since the circumstances will vary consid ­
erab ly between one coll ision and another. I mportant factors
inc lude, for example, the nature (hard or soft) of the impacting
object, the angle o f impact, vehicle speed,
etc .=> page 205, "I m por ­
tant safety instructions on the side airbag system".
Aside from their normal safety funct ion, safety be lts work to help
keep the driver or front passenger in posit ion in the event of a side
collision so t hat the side airbags can provide protection.
The airbag system is
not a substitute for your safety belt. Rather, it
is part of the overa ll occupant restraint system in your vehicle .
A lways re m ember that t he side airbag system can on ly he lp to
protect you if you are wearing your safety be lt and wearing it prop ­
e rly. This is a nother reason why yo u should a lways wear you r safety
belts, not just because the law requires you to do
so=> page 176,
"General notes".
It is important to re m em ber that while the supp lemental side airbag
system is designed to reduce the like lihood of serious injuries, other
injuries, for example, swel ling, bru is ing, and minor abrasions can
a lso be associated with deployed side airbags. Remember too, side
a irbags wil l deploy o nly once and on ly in certain kinds of accidents
- your safety belts are a lways there to offer protection.
Vehicle damage, repair costs or even the lack of vehic le damage are
not necessari ly an indication of over-sensitive or failed airbag acti ­
vation. In some collisions, both front and side airbags may inflate.
Reme mber too, that a irbags w ill dep loy on ly once and on ly in
certain kinds of col lisions -your safety belts are always there to
offer pro tec tion in those acc ide nts in whic h airbags are not
supposed to deploy or when they have already deployed. T
he s ide a irbag sys te m will not d eplo y:
• whe n the ign ition is turned off
• in side collisions when the acce leration measured by the sensor
is t oo low
• in front-end co llisions
• in rear-end co llisions
• in ro llovers .
I n some types of accidents the front airbags, side curta in airbags
and side airbags may be triggered together.
& WARNING
• Safety belt s and the airbag sy stem will only prov ide protection
when occupant s are in the proper se ating posit ion
=> page 2 05 .
• If the airbag indic ator light come s on when the vehicle i s being
u sed , ha ve the sy stem inspe cted immed iat ely by y our authorized
Audi d ealer . The airbag may not work properly when the vehicle
a cc eler ation in a side colli sion is high enough to acti vate the
airba g.•

How supplemental side airbags work
Side airbags deploy instantly and can help reduce the risk
of upper torso injuries for occupants wh o are properly
restrained.
i w CD
"'
F ig . 18 2 Infl ate d side
airba gs on l eft sid e o f
v eh icle, rear s ide
air bag o ptional
equ ip­
ment
When the system is triggered, the airbag is fi lled with propel lant 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 o f a second a t very high
speed and with great force. The supplemental side airbag could
injure you if your seating pos it ion is not proper or upright or if items
are located in the area where the supplemental side airbag expands.
This app lies especially to
children => page 210, "Child Safety" .
Supplemental side airbags inflate between the occupant and the
door pane l on the side of the vehicle that is struck in certain side
coll ision
=> fi g. 182 .
A lthough 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 .
Safety first
Airbag syst em
A fine dust may develop when the airbag deploys . This is normal
and does not mean there is a fire in the vehic le .•
Important safety instructions on the side
airbag system
Airbags are only supplemental restraints. Al ways prop­
erly wea r s afet y belts and ride in a pro per seati ng posi­
tion.
There is a lot that you and your passengers must know and act
accordingly to help the safety belts and ai rbags do their job to
provide supplementa l protection.
& WARNING
An inflating s ide airbag can cau se seriou s or f ata l injury . Imp rop ­
erly wear ing safety belts and improper seating pos ition s increase
the r isk of ser iou s per sonal injury and death whenever a vehicle i s
being used .
• In order to reduce the ri sk of injury when the suppleme nta l si de
airbag inflate s:
- Always sit in an upright po sition and never lean against the
area where the supplemental side airbag i s located .
- Never let a child or anyone else re st the ir head against the
s ide trim panel in the area where the supplement al side airbag
i nflate s.
- Alway s make sure that safety belt s are w orn correctly ,
-Do not let anyone sitting in the front seat put their h and or
any other part s of th eir body out of the windo w.
• Alway s make sure that the side airbag c an inflate without inter ­
feren ce .
- Never install seat covers or replac ement uphol ste ry ov er the
fr on t seat b acks that have not been spe cifi ca lly approved by
Audi .
...
irechnical data

Side curtain airbags (SIDEGUARD™)
Description of SIDEGUARD™ airbags
The SIDEGUARD™ airbag system can provide supple­
mental protection to properly restrained occupants.
F ig . 18 3 S IDEGUARD ™
sys tem , driver's s id e:
s id e cu rtain air b a g
l oca tio n
The side curtain airbags are located on both sides of the interior
above the front and rear side
windows => fig. 183 . 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 s ide of the vehicle that is struck in a side collision . The
side curtain airbag inflates only in side impacts and only when the
vehicle accele ra tion reg istered by the contro l unit is high enough. If
this rate is below the reference va lue programmed into the contro l
unit, the side airbags w ill not be triggered, even though the car may
be badly damaged as a result of the co llision . It is not possible to
define an airbag triggering range that will cover every possible
angle of impact, since the circumstances will vary considerably
between one collision and ano the r. Important factors include, for
example, the nature (hard or soft) of the impacting object, the angle
Safety first
Airb ag syst em
of impact, vehicle speed, etc .=> page 208, "How side curtain airbags
work".
Aside from their norma l safety function, safety belts work to help
keep the driver or front passenger in position in the event of a colli ­
s ion so that the side curtain airbags can provide protection .
The airbag system is not a substitute for your safety belt . Rather, it
is part of the overall occupant restrain t system in your veh icle.
Always remember that the airbag system can only he lp to protect
you if you are wear ing your safety belt and wear ing 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 176, "General
notes".
It is important to remember that while the side curtain airbag
system is designed to help reduce the likelihood of serious injuries,
other injuries, for examp le, swelling, bruising, and minor abrasions
can a lso be associa ted with these a irbags . Remembe r too, these
airbags will deploy only once and on ly in certain kinds of accidents
- your safety belts are always there to offer protection .
The side curta in air b ag system b asi cally consists of :
• The elec tronic co ntrol mod ule and external side impact sensors
• The side curtain airbags above the front and rear side windows
• The airbag indicator light in the instrument panel
The airbag system is monitored electronica lly to make certain it is
f u n ction ing properly at all times. Each time you turn on the ignition,
the airbag system indicator light wi ll come on for a few seconds
(se lf diagnostics).
The s ide curt ain ai rbag is not acti vated :
• if the ignition is turned off,
• in side collisions when the acceleration measured by the sensor
is too low,
• in front -end collisions,
• in rear -end collisions,
.,
irechnical data

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=-- s
-=- y_s _t _e _m _________________________________________________ _
• in rollovers.
& WARNING
• Safety belts and the airbag system will only provide protection
when occupants are
in the proper seating position ~ page 95,
"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.
•
How side curtain a irbags work
Side curtain airbags con work together with side airbags
to help reduce the risk of head and upper torso injuries for
occupants who ore properly restrained.
Fig . 184 Illustration of
principle: Inflated side
curtain airbags on the
left side
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 . 184. 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
inflate within the blink of an eye at very high speed and with great
force. 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 supplemental side curtain airbag inflates. This applies espe ­
cially to
children~ page 210.
Although they are not a soft pillow, 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 vehicle .•
Important safety instructions on the side
curtain airbag system
Airbags ore 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 their 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 .
• Never let occupants place any parts of their bodies in the area
from which the side curtain airbags inflate.
• Always make sure that the side curtain airbags can inflate
without interference. Unsuitable accessories fitted inside the

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& WARNING (continued)
expansion range of a SIDEGUARD head airbag can dangerously
interfere with its function. A deploying head airbag develops
enough force to catapult any piece of add-on component out of its
path of inflation and into the passenger compartment. An occu­
pant hit by such a projectile can suffer serious injury or death
=> page 349, "Technical Modifications".
• Do not swivel the sun visors to the side if you have any objects
clipped onto them (for example
pens!. If the airbag should deploy,
you could be injured by these objects.
• 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 airbag deployment and can cause personal injury in
an accident.
• Never use hangers to hang clothing from the hooks.
• Only use factory-installed sun shades or, in the case of shades
installed after the vehicle leaves the factory, only Audi roll-up
sunscreens may be used => page 348, "Additional accessories and
parts replacement".
• Always sit in proper seating position and wear safety belts
while traveling so that the side curtain airbags can help provide protection .
• The airbag system can only be triggered once. If the airbag has
been triggered, the system must be replaced by an authorized
Audi dealer or qualified workshop.
• Always have work involving the side curtain airbag system,
removal and installation of the airbag components, or other
repairs performed by a qualified dealership. Otherwise the airbag
system may not work correctly.
• Never attempt to modify any components of the airbag system
in any way. •
Controls and equip­ ment Safety first
Vehicle operation Vehicle care Do-it-yourself service Technical data