2018 AUDI S4 airbag

Airbag syste m
front seat p assenge r's frontal Advanced Airbag.
Th e PAS SENGER AIR BAG
OFF ~; light:
-will come o n if the front pa ssenger seat is not
occupied;
- will come on if the e lectr ica l capacitance meas­
u red by the c apac itive passenger detec tion sys ­
tem for the front passenger seat equals the
combined capacitance of an infant up to about
one year of age and one of the rearward-facing
or forward-facing child rest raints listed in Fed­
eral Motor Vehicle Safety Standard 208 with
which the Advanced Ai rbag System in your veh i­
cle was certif ied; Fo r a listing of the child re­
straints that were used to cert ify your vehicle's
compliance with the U .S. Safety Standard
¢ page 297.
-will go out if the front passenger seat is occu­
pied by an adult as reg istered by the capacitive
passenger detection system.
- T he
PAS SENG ER AIR BAG OFF ~; light must
come on and s tay o n if the ignition is on and . ..
- a car bed has been insta lled on the front pas­
senger seat, o r
-a rearward-fac ing ch ild restrai nt has been in­
stalled on the front passenger seat , or
- a forward-facing child restra int has bee n in stal ­
led on the front passenger seat,
- and if the e lectrical capacitance registered on
the front passenger seat is equa l to or less than
the comb ined capac itance of a typical 1 year­
o ld infant and one of the rearward-fac ing o r
fo rward -fa cing chi ld restrain ts lis ted in Federal
Motor Veh icle Safety Standard 208 with w hich
the Advanced Airbag System in yo ur vehicle was
certified .
If th e fron t passe nger seat is no t occ upied, the
front ai rbag w ill not dep loy, and the
PASSENGER
AIR BAG
OFF ~; light wi ll stay on.
Never i nstall a rearward-facing child rest raint on
t he front passenge r sea t, the safes t place for a
chi ld in any k ind of child restraint is at one o f the
seating positions on the rea r seat ¢
page 2 72,
Child restraints on the front seot -some impor­
tant things to know
and ¢ page 295, Child safe ­
ty .
284
If the PASSENGER AIR BAG OFF ~; light
com es on ...
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 regularly to make
certain t hat the
PASSENGER AIR BAG OFF ~;
light stays on cont inuously whenever the ign ition
i s on . If the
PASSENGER AIR BAG OFF ~; light
does not appear on and does not stay on all the
time, stop as soon as it is safe to do so a nd
- reactivate the system by tur ning the ignit ion
off for more than 4 seconds and then tur ning it
on
again;
- remove and re install the ch ild restraint. Make
sure that the child restra int is prope rly insta l­
led and that the safety belt for the front pas­
senge r sea t has bee n corre ct ly rou ted th rough
t he child restraint as desc ribed in the ch ild re­
straint man ufact urer's inst ruc tions;
- ma ke sure that the convert ible loc king retr ac­
to r on the safety belt for the front passenge r
seat has been activated and that the safety belt has been pulled tight .
- ma ke sure that no e lectrica l device (s uch as a
laptop , CD p layer , e lectronic games device,
power inverte r or seat heater for chi ld seats) is
placed or used on the front passenger seat if
the device is connected to the 12-volt socket or
the c igarette lighter socket;
- make sure that no seat heater has been retro­
fitted or otherw ise added to the front passen­
ger seat;
- make sure that noth ing can interfere with the
safety belt buckles and that they are not ob­
struc ted;
- make sure that there are no wet objects (such
as a wet towe l) and no water or other liquids on
the front passenger seat cushion .
If the PASSENGER AIR BAG OFF~; light still
does not come on ...
If the PASSENGER AIR BAG OFF~; light st ill
does not come on and does not stay on cont in u­
ous ly (when the ign ition is switched o n),
- take the child restra int off the front passenger
seat and install it properly at one of the rear
ll-

a co .... N ,....
N .... 0 0
3 co
seat positions. Have the airbag system inspect­
ed by your Audi dealer immediately .
- move the chi ld 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.
Th e PASSENGER AIR BAG OFF ~ ; light
s h ould NOT com e on ...
The PASS ENGER AI R BAG OFF ~ ; light should
NO T come on when the ignition is on and an
adult is sitting in a proper seating position on the
front passenger seat . If the
PASS ENGER AIR
BAG
O FF ~; light comes on and stays on while
driving, under these circumstances, make sure
that :
- the adult on the front passenger seat is proper­
ly seated on the center of the seat cushion with
his or he r back up aga inst the backrest and the
back rest is not reclined,
- the adult is not tak ing weight off the seat by
ho lding on to the passenger assist handle
above t he front passenger door or supporting
their we ight on the a.rm rest ,
-the safety belt is be ing properly worn and that
there is not a lot of slack in the safety belt web­
bing,
- there are no aftermarket seat covers or cush ­
ions or other things (such as blankets) on the
front passenger seat that migh t ca use the ca­
pacitive passenger detection system to miscal­
cu late electrical capacitance .
Important safety instructions on
monitoring the Advanced Airbag System
A WARNING
- If the status of the Adv a need A irbag System
has changed while the vehicle is moving, the
PASSENGER AIR BAG OFF ,;; ON @ light
blinks for about 5 seconds to catch the driv­
er's attention .
If this happens, always stop
as soon as it is safe to do so and check the
steps described above .
- If the
PASSENGER AIR BAG OFF ,;; light
does not go off when an adult who is not
very small is s itting on the front passenger
-
Airb ag sys tem
seat after taking the steps described above,
make sure the adu lt is properly seated and
restrained at one of the rear seating posi­
tions . Have the a irbag system inspected by
your author ized Audi dealer before trans­
port ing anyone on the front passenger seat.
A WARNING
f-
An a irbag system that is not functioning prop-
e rly cannot prov ide supplemental protect io n
i n a front al crash.
- I f the ai rbag ind icator light
~page 32
comes when the veh icle is being used, have
the system inspected immedia tely by your
authorized Audi dealer . It is possib le that
the airbag will inflate when it is not sup­
posed to, or will not inflate when it should.
A WARNING
If the front airbag inflates, a ch ild without a
chi ld restraint, or in a rearward-facing child
safety seat, or in a forward-fac ing child re­
stra int that has not been properly insta lled
will be seriously injured and can be killed.
- Even though your vehicle is equipped with
an Advanced A irbag System, make certain
that all children , espec ially 12 years and
younge r, always ride on the back seat p rop­
erly rest rained for the ir age and s ize .
- Always install fo rwa rd or rear-facing child
safety seats on the rear seat - even with an
Advan ced Airbag System.
- I f you must install a rea rwa rd-facing child
safety seat on the front passenger seat be­
cause of excep tional circums tances and the
PASSENGER AIR BAG OFF ,;, light does not
appear and stay on, immediate ly install the
rear-facing chi ld safety seat in a rear seat ing
position and have the a irbag system in­
spected by your authori zed Aud i dea ler.
- If, in exceptional circumstances, you must
install a forward-facing child restraint on
the front passenger seat, always move the seat into its rearmost position in the seat's
fore and aft ad justment range, as far away
from the a irbag as poss ible . The back rest
m ust be adjusted to an upr ight position .
285

Airbag syste m
Make sure that the PASSENGER AIR BAG
OFF
11;; li ght comes on and stays on all t he
t ime whenever the ignition is switched on.
A WARNING
- If the PA SSEN GER AIR BAG OFF 11;; light
does not go ou t when an adult is sitting on
the front passe nger seat a fte r ta king the
steps described above, make sure the adult is p roperly seated and restrained at one of
the rear seating positions.
- Have the airbag system inspected by your
authorized Aud i dealer before transporting
anyone on the front passenger seat.
@ Tips
If the capacitive passenger detection system
determines that the front passenger seat is
empty, the frontal airbag on the passenge r
side w ill be tu rned off, and the
PASSENGER
AIR BAG OFF
11;; light will stay on.
-
Repair , care and disposal of the airbags
Parts of the a irbag system are installed at many
different places on your Audi. Installing, remov­ ing, servic ing or repa iring a part in an area of the
ve hicle can damage a part of an airbag system
and prevent that system from working properly
i n a collision .
There are some important things you have to
know to make sure that the effectiveness of the
system w ill not be impaired and that discarded
components do not cause injury or pollute the
env ironment.
A WARNING
Improper care, serv icing and repai r proce­
dures can increase the r is k of personal injury
and death by preventing an airbag from de­
ploying when needed or dep loying an airbag
unexpectedly:
-
- Never cover, obstruct, or change the steer ­
ing wheel horn pad or airbag cover or the in­
strument pane l or modify them in any way.
286
- Never attach any objects s uch as c upholders
or telephone mountings to the surfaces cov­
ering the a irbag un its.
- For cleaning the horn pad or instrument
panel, use only a soft, dry cloth or one mois­
tened w ith plain water. Solvents or cleaners
could damage the airbag cover or change
the st iffness or strength of the material so
that the airbag cannot deploy and p rotect
properly.
- Never repair, adjust, or change any parts of
the airbag system.
- All work on the steering wheel, inst rument
panel, front seats or e lectr ica l system ( in­
cluding the installation of a udio eq uipment,
cellular telephones and C B radio s, etc.)
m ust be perfo rmed by a qualified techn ician
who has the training and specia l equipment
necessary.
- For any work on the airbag system, we strong ly recommend that you see your au­
thorized A udi dealer or qualified workshop.
- Never modify the front b umper or parts of
the vehicle body.
- Always make sure that the side a irbag can
inflate w ithout interference:
- Never install seat covers or replacement
u pholstery ove r the front seatbacks that
have not been specifically approved by
A udi.
- Never use additional seat cushions that
cover the areas where the side airbags in­
flate.
- Damage to the orig inal seat cove rs or to
the seam in the area of the s ide airbag
module mus t always be repaired immedi­
ate ly by an authori zed Au di dealer.
- The a irbag system can deploy on ly once. Af­
ter an airbag h as been deployed, i t m ust be
repla ced with new replacement parts de­
signed and approved espec ia lly for your
Audi model version . Replacement of com­
plete airbag systems or airbag components
must be perfo rmed by qua lified workshops
only. Make sure that any airbag service ac­
tion is entered in your A udi Warranty
&
Ma intenance boo klet under AIRBAG RE-
PLAC EM EN T RECORD.
~

-For safety reasons in severe accidents, the
alternator and starter are separated from
the vehicle battery with a pyrotechn ic circuit
interrupter.
-Work on the pyrotechnic circ uit interrupt ­
er must only be performed by
a qualified
technicians who have the experience, in ­
formation and special tools necessary to
perform the work safely.
-I f the vehicle or the circuit interrupter is
scrapped, all app licab le safety precautions
must be followed .
@) For the sake of the environment
Undeployed airbag modu les a nd pretension ­
ers might be classified as Perch lorate Materi­
al
-special handling may apply, see
www.dtsc .ca.gov/hazardouswaste/perchlo­
rate. When the vehicle or parts of the re­
straint system including airbag modules and
safety belts with pretensioners are scrapped,
all applicable laws and regulations must be
observed. Your authorized Audi dealer is fa­
m iliar with these requi rements a nd we recom­
mend t hat you have you r dealer perform this
service for you.
Other things that can affect Advanced
Airbag performance
Changing the vehicle's suspension system can
change the way that the Advanced Airbag System performs in a crash . For example, using tire-r im
comb inat ions not approved by Audi, lowering the
ve hicl e, chang ing the stiffness of the suspens io n,
in clud ing the spr ings, suspens ion str uts, shock
absorbers et c. can change the forces that are
measured by the airbag sensors and sent to the
e lectronic contro l unit. Some suspension changes
can, for example, increase the force levels meas­
ured by the sensors and make the airbag system
deploy in crashes in wh ich it would not deploy if
the changes had not been made. Other ki nds of
changes may reduce the fo rce levels meas ured by
the sensors and prevent the airbag from deploy­
in g when i t should .
Airbag sys tem
A WARNING
-Changing the vehicle's suspension including
use of unapproved tire-rim combinations can
change Advanced Airbag performance and in­
crease the risk of serious persona l injury in a
crash.
- Never install suspension components that
do not have the same pe rformance charac­
teristics as the components o rigina lly ins tal­
led on your vehicle.
- Never use tire-rim combinations t hat have
not been approved by Audi.
Knee airbags
Description of knee airbags
The knee airbag system can provide supplemen­
tal protection to prop erly restrained front sea t
occupants.
F ig. 2 42 D river 's knee a irbag
The driver knee airbag is in the instrument panel
u nderneath the steering whee l
~fig. 242, the
airbag fo r the p asse nger is at about the same
height in the instr ument pane l underneath the
glove compa rtment.
T he knee airbag offers add itiona l protection to
the driver's and passenge r's knees and uppe r and
lower thigh areas and supp lements the protec­
tion provided by the safety be lts .
If the front airbags deploy, the knee airbags a lso
deploy in fron tal coll is ions when the deploymen t
threshold stored in the cont rol un it is me t
~ page 281, More important things to know
about front airbags.
287

Airbag system
In addition to their normal safety function, safe­
ty belts help keep the driver or front passenger in
position in a frontal collision so that the airbags
can provide supplemental protection.
The airbag system is not a substitute for your
safety belt. Rather, it is part of the overa ll occu­
pant restraint system in your vehicle. Always re­
member that the airbag system can only help to
protect you if you are wearing your safety belt
and wearing it properly . This is why you should
always wear your safety belt, not just because
the law requires you to do so ¢
page 263, Gener­
al information.
Remember too, airbags will deploy only once and
only in certain k inds of accidents - your safety
belts are always there to offer protection in those
accidents in which airbags are not supposed to
deploy or when they have already deployed, for
examp le when your vehicle str ikes or is struck by
another after the first collision .
This is jus t one of the reasons why an airbag is
not a substitute for the safety belt. The a irbag
system works most effectively when used with
the safety belts. Therefore, always wear your
safety belts correct ly.
It is important to remember that while the sup­
p lemental knee airbag system is designed to re­
duce the likelihood of serious injuries, other inju ­
ries, for example, swe lling, bruising and minor
abrasions and friction burns can also occur when
an airbag inf lates .
The knee airbag system basically consists of:
- T he electronic control module
- T wo inflatab le airbags (airbag and gas genera-
to r), one for the driver and one for the front
pass enger
- The airbag indicator ligh t in the instrument
panel
The knee airbag system will not deploy:
-whe n the ignition is switched off
- in frontal collisions when the deceleration
measured by the control un it is too low
- in side collisions
- in rea r-end collisions
288
-in rollovers
- in the event of a system malfunction (warning/
ind icator light is on)
¢page 32 .
A WARNING
-Safety belts and the airbag system can only
provide protection when occupants are in
the proper seating
position ¢ page 281 .
-If the airbag indicator light ¢ page 32
comes when the veh icle is being used, have
the system inspected immediately by your
author ized Audi dealer. It is possible that
the airbag will inflate when it is not sup­
posed to, or will not inflate when it should.
How knee airbags work
The risk of injury to the leg area con be reduced
by fully inflated knee airbags.
Fig. 243 In flated a irbags protect ing in a fro nta l coll ision
The knee airbag system has been designed so
that the airbags for the dr iver and front passen­
ger dep loy in certain but not all fronta l collisions .
If the front airbags deploy, the knee airbags also
deploy in frontal collisions when the deployment
threshold stored in the control unit is met .
When the system deploys, the airbags fill with a
prope llant gas, and inflate between the lower
part of the instrument panel and the driver and
the lower part of the instrument panel and the
front passenger
¢page 281, fig. 240 .
Although they are not a soft pillow, they can
"cushion" the impact and in this way they can
help to reduce the risk of injury to the lower ex­
tremities.

All of this takes place in the blink of an eye, so
fast that many people don't even realize that the airbags have deployed . The airbags also inflate
with a great deal of force and it is important for
occupant safety that nothing should be in their
way when they deploy .
Fully inflated airbags in comb ination with proper­
ly worn safety belts slow down and limit the oc­
cupant 's forward movement and help to reduce
the r isk of injury .
Important safety instructions on the knee
airbag system
Airbags are only supplemental restraints . Always
wear safety belts correctly and ride in a proper
seating position.
There is a lot that you and your passengers must
know and do to help the safety be lts and airbags
to provide s upplemental protection .
,& WARNING
An inflating knee airbag can cause ser ious in­
jury. Wearing safety bel ts incor rectly and im­
proper seating posit ions increase the r isk o f
serious personal injury and death whenever a
vehicle is being used.
- The knee airbag system cannot protect you
prope rly if you are seated too close to any of
the a irbag locat ions. When ad justing their
seat positions, it is important that both the
dr iver and the front passenger keep their
upper bod ies a nd knees at the following
min imum safe d istances:
- at least 10 inches (25 cm) between the
chest and the steering wheel/instrument
panel.
- at least 4 inc hes (10 cm) between the
knees and the lower part of the instru­
ment panel.
- The risk of persona l injury increases if you
lean forward or to the side, or if the seat is
improper ly positioned and you are not wear­
ing your safety belt. The risk increases even
more should the a irbag deploy.
- Always make sure that the knee airbag can
inflate without interference. Objects
be-
Airb ag sys tem
tween you and the airbag can increase the
risk of injury in an accident by interfering
wit h the way the airbag deploys or by being
pushed into yo u as the a irbag deploys.
- Never let anybo dy, especi ally children or
anima ls r ide in the footwell i n front of the
passenger seat. If the airbag deploys, this
can result in serious o r fatal in juries.
- Never carry objects of any kind in the foo t­
well area in front of the driver's or pas­
senger's seat . Bulky objects (shopp ing
bags, for example) can interfere with or
prevent proper dep loyment of the airbag.
Small objects can be thrown th rough t he
vehicle if the airbag deploys and injure you
o r your passengers.
- Make sure the re a re no cracks, deep scratch­
es o r othe r damage in the area of the inst ru­
ment panel where the knee airbags a re lo­
ca ted.
- If ch ildren are incorrectly seated, their risk
of injury inc reases in a coll is ion
~ page 29 5, Child safe ty.
Side airbags
Description of side airbags
The airbag system can provide supplemental
protection to properly restrained occupants.
Fi g. 2 44 Side a irbag locat ion in the drive r's sea t
The side airbags are located in the s ides of the
front seat
backrests ~ fig. 244 and the rear back­
res t* facing the doo rs.
The side airbags installed for the front seating
pos itions have been des igned and certified to
help reduce the risk of in ju ry that can be caused
by a irbags when they inflate, pa rticul arly when
.,.
289

Airbag system
the occupant sitting next to it is not seated prop­
erly. The side airbag for the front passenger seat
can be used with properly installed child re­
straints. Please be sure to read the important in­
formation and warnings whenever using a child
restraint in a vehicle: Safety belts
Qpage 263,
Airbag system Qpage 271, Ch ild safety
c::;, page 295.
The side airbag system basically consists of:
-the e lectronic control modu le and externa l side
impact sensors
- the two side airbags located in the sides of the
front backrests
- two rear side airbags*
- the airbag warning light in the inst rument clus -
ter.
The airbag system is monitored electronically to make certa in that it is functioning properly at all
times. Each time you turn on the ign it ion, the air­
bag system indicator light will come on for a few
seconds (self diagnostics).
The side airbag system supplements the safety
be lts 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 co llision. The a irbag dep loys only in side im­
pacts and on ly when the vehicle acceleration reg­
istered by the control unit is high enough . If this
rate is below the reference value programmed in­
to the control un it, the side airbags will not be
tr iggered, even though the car may be badly
damaged as a result of the collision.
It is not pos­
sib le to define an a irbag tr igger ing range that
will cover every possible angle of impact, since
the circumstances will vary considerably between
one collision and another . Important factors in­
clude, for example, the nature (hard or soft) of
the impacting object, the angle of impact, vehicle
speed, etc.
Q page 291, Important safety in­
structions on the side airbag system.
Aside from their normal safety function, safety be lts work to help keep the driver or front pas­
senger in pos it ion in the event of a s ide collision
so that the side a irbags can provide protection.
The airbag system is
not a subst itute for your
safety belt. Rather, it is part of the overall occu-
290
pant res traint system in your vehicle . Always re­
member that the side airbag system can only
help to protect you if you are wear ing your safety
belt and wearing it properly. This is another rea­
son why you should a lways wear your safety
belts, not just because the law requires you to do
soc::;, page 263, General information .
It is important to remember that while the sup­
plemental side airbag system is designed to re­
duce the likelihood of ser ious injuries, other inju­
ries, for example, swelling, bru is ing, friction
burns and minor abrasions can also be assoc iated
with deployed side airbags. Remember too, side
a irbags w ill dep loy only once and only in certa in
kinds of accidents
-your safety belts are always
there to
offer protection.
Vehicle damage, repair costs or even the lack of
vehicle damage are not necessarily an ind icat ion
of over-sens itive or fa iled airbag activation. In
some collisions, both front and side airbags may
inflate. Remember too, that airbags wi ll deploy
on ly once and only in certain kinds of collisions
-
your safety be lts are always there to offer protec­
tion in those accidents in which airbags are not
supposed to deploy or when they have already
deployed .
The side airbag system will not deploy:
- when the ignition is turned off
- in side co llisions when the acceleration meas -
ured by the sensor is too low
- in front-end collisions
- in rea r-end collisions
- in rollovers.
In some types of accidents the front airbags, side
curta in airbags and side a irbags may be triggered
together .
&_ WARNING
-Safety belts and the airbag system will only
provide protection when occupants are in
the proper seating position
Q page 291.
- If the airbag indicato r light Q page 32
comes when the vehicle is being used, have
the system inspected immediately by your
authorized Audi dealer. It is possible that

the airbag will inflate when it is not
supposed
to, or will not inflate when it
should.
How supplemental side airbags work
Side airbags deploy instantly and can help re­ duce the risk of upper torso injuries for occu­
pants who are properly restrained.
Fig. 245 Infla ted side airbags on left side of veh icle, rear
side airbag opt ional equipment
When the system is triggered, the airbag is filled
with propellant gas and breaks through a seam in
the seat surface area.
It expands between the
side trim panel and the passenger. In order to
help provide this additional protection, the side
airbag must inflate within a fraction of a second
at very high speed and with great force . The sup­
plemental side airbag could injure you if your
seating position is not proper or upright or if
items are locat ed in the area where the supple­
mental side airbag expands. This applies espe­
cially to
children¢ page 295, Child safety. Sup­
plemental side airbags inf late between the occu­
pant and the door panel on the side of the vehicle
that is struck in certain side
collision ¢ fig. 245.
Although they are not a soft pillow, they can
"cushion" the impact and in this way they can
help 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 .
Airbag system
Important safety instructions on the side
airbag system
Airbags are only supplemental restraints. Always
properly wear safety belts and ride in a proper
seating position .
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 supplemental
protection.
A WARNING
An inflating side airbag can cause serious or
fatal injury. Improperly wearing safety belts
and improper seating positions increase the
risk of serious personal injury and death
whenever a vehicle is being used.
- 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 supple­
mental 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 interference.
- Never install seat covers or replacement
upholstery over the front seatbacks that
have not been specifically approved by
Audi.
- Never use additional seat cushions that
cover the areas where the side airbags de­ ploy.
- 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 in­
crease the risk of injury in an accident by in­
terfering with the way the airbag unfolds or
_,.
291