2018 AUDI A3 SEDAN sensor

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Active rollover protection system
Function
Applies to: vehicles wit h power top
The rollover protection system protects vehicle
occupants in the event of a rollov er.
........ ..._____ ----
F ig. 220 Re ar seats: rol lb ar deploy men t ran ge
----
Fig. 221 Rear seats: deployed rollbar
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The ac tive rollover prote ction sys tem consists of :
- two ro llbars
- the safety belts with belt tensioners
- the windshie ld frame
- the rollover sensors
The active rollover prote ction system provides
additional sa fety in the event of a rollover . With­
in m illiseconds, sensors deploy two rollbars lo ­
cated behind the head restraints in the rear seats
¢ fig. 221 .
The rollbars, re inforced windshield frame and
belt tensioners help protect front and rear pas ­
sengers in the event of a rollover .
The rollover protec tion system functions when
t he power top is both open and closed .
Dri ving safety
A WARNING
Do not use the area behind the rear seat head
restraints
¢ fig . 220 as a seat or storage area .
This is the area where the rollbars deploy . If
the rollover protection system is t riggered,
objects placed there can be p ropelled th rough
the veh icle and ma ke it more diffic ult for the
r ollbars to deploy. This increases the risk for
serious or life -threatening injuries.
When is rollover protection deployed?
Applies to: veh icles w ith power top
Rollover protection deploys in a collision or roll­
over.
Depend ing on the co llision, senso rs thro ughout
the vehicle and the co ntro l modu le trigger the
rollove r system to deploy.
For safety reasons, rollover protection also de­
ploys during front, s ide and rear collisions above
a certain level of severity.
Retracting rollover protection
Applies to: veh icles w ith power top
Fig . 222 De ployed ro llbar wi th release loo p.
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Fig. 223 De ployed ro llbar w ith powe r to p frame facing up·
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Airbag System for the front passenger seat from
doing its job in a crash.
The front Ad vanced Airbag System con sists
o f th e follo wing :
-Cras h sensors in the front of the vehicle that
measure vehicle acceleration/deceleration to
provide information to the Advanced Airbag
System a bout the severity of the crash.
- An electronic control unit, with integrated
crash sensors for front and side impacts. The
contro l unit "decides" whether to fire the front
airbags based on the information received from
the crash sensors . The control unit also "de­
c ides" whether the safety belt pretens ioners
shou ld be activated .
-An Advanced Airbag with gas generator for the
dr iver inside the steering wheel hub.
-An Advanced Airbag with gas generator ins ide
the instrument panel for the front passenger.
-A capac itive passenger detect io n system under­
neath the front passenger seat cover. This sys­
tem measures the elect rical capac ita nce of the
person in the seat. The info rmat ion registe red
is sent cont inuous ly to the electro nic cont rol
u nit to regula te deployment of t he front Ad ­
vanced Airbag on the passenge r side.
-An a irbag monito ring system and indica tor
li gh t in the ins trument
cluste r¢ page 281 .
-A se nso r in each front seat reg isters the dis ­
tance between the respec tive sea t and the
steering wheel or instrument pane l. The infor ­
mation registered is sent continuous ly to the
electronic control unit to regulate deployment
of the front Adv a need A irbags.
-T he PASSENGER AIR BAG OFF light comes on
and stays on in the center of the instrument
panel
¢ page 318 and tells you when the front
Advanced Airbag on the passenger side has been turned off .
-A sensor in the safety belt latch for the driver
and for the front seat passenger that senses
whether that safety belt is latched or not and
transm its this info rmat ion to the elect ronic
contro l unit.
Airbag syste m
.&, WARNING ~ -
Damage to the front passenger seat can pre­
vent the front airbag from working properly.
-Improper repair or disassembly of the front
passenger and driver seat will p revent the
Advanced Airbag System from f unct ion ing
p roperly.
-Repairs to the front passenger seat must be
pe rformed by qualified and p roperly trained
wo rkshop personne l.
-Never remove the front passenger or driver
seat from the vehicle .
-Never remove the upholstery from the front
passenger seat.
-Never d isassemble or remove parts from the
seat o r disconnect w ires from it.
-Never carry sharp objects in your pockets or
put them on the seat. The capacit ive pas­
senger de tect ion mat in the front passenger
seat will not function p roperly if i t is punc­
tured.
-Never carry things on your lap or carry ob­
jects on the front passenge r seat. S uch ob­
jects can influence the capacitance reg is­
tered by the cap aci tive passenger detection
sys tem, so that incorrect in formation is pro­
vided to the ai rbag control unit.
-Never store i tems unde r the front passenger
seat . Parts of the Advanced Airbag System
under the passenger seat could be dam­
aged, p reventing them and the airbag sys­
tem from wor king p roper ly.
-Never p lace seat covers or replacement up­
holstery that have not been specifically ap­
proved by Audi on the front seats.
-Seat covers can prevent the Advanced Air­ bag System from recognizing chi ld re­
stra ints or occupants on the front passenger
seat and prevent the side airbag in the seat
backrest from deploying properly.
-If a seat heater has been retrofitted or oth­
erwise added to the front passenger seat,
never ins tall any child restra int system on
this seat.
-Never use cushions, p illows , blankets, or
similar items on the front passenge r seat .
T he addi tional laye rs prevent the capacit ive
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Airbag syste m
passenger detection system from accurately
measuring the capac itance of the ch ild safe­
ty seat and/or the person on the seat and
thus keep the Advanced Airbag System from
working properly .
- Never place or use any electrical device
(such as a laptop, CD player, electronic
games dev ice, power inverter or seat heater
for child seats) on the front passenger seat
if the device is connected to the 12-volt
socket or the cigarette lighter socket. S uch
devices can infl uence the capacitance reg is ­
tered by the capacitive passenger detection system, so that incorrect information is pro­
vided to the airbag control unit.
- If you must use a child restraint on the front
passenger seat and the child restraint man­
ufacturer 's instructions require the use of a
towel, foam cushion or something else to
properly position the ch ild restraint, make
certain that the
PASSENGER AIR BAG OFF
l ight comes on and stays on whenever the
child restraint is installed on the front pas­
senger se at.
- If the PASSENGER AIR BAG OFF light does
not come on and stay on, immedia tely in­
st al l child res traint in a rear seating posi tion
and have the airbag system inspected by
yo ur Audi dealer.
A WARNING
If the front passenger seat gets wet, dry it im­
mediately .
- If liquid soaks into the front passenger seat,
this can keep the airbag system from work­
ing properly and may, for instance, deact i­
vate the passenger frontal airbag. If this
happens, the
PASSENGER AIR BAG OFF
light will come on and stay on together with
the a irbag indicator light
m in the instru­
ment cluster.
- If liquid is poo led on the seat, but has not
soa ked in, this may also keep the airbag sys­
tem from wo rking properly and ca use the
passenge r frontal a irb ag to be enabled
(tu rned on), even though there is a properly
installed chi ld restraint system on the seat.
278
Wet towels or other wet things on the seat
cushion can have the same effect. If the
front passenger fronta l airbag is turned on,
the
PASSENGER AIR BAG OFF light will go
out .
How the Advanced Airbag System
components work together
The fro nt Advanced A irbag System and t he side
airbags supp lement t he protection offered by the
front t hree-point safety be lts and the adjustable
head restraints* to help red uce the risk of inj ury
i n a wide range of accident and crash sit uations.
Be sure to read the important information about
safety and heed the WARNINGS in this chapter.
Deployment of the Advanced Airbag System and
the activation of the safety belt pretensioners de ­
pend on the dece leration measured by the crash
sensors and registered by the electronic contro l
unit . Crash severity depends on speed and decel­
e ration as well as the mass and stiffness of the
vehicle or object involved in the crash.
On the passenger side, regardless of safety belt
use, the front passenger frontal a irbag will be
turned off if the electr ica l capacitance measured
by the capacitive passenge r detection system o n
t h e front passenger seat is less tha n the amount
prog rammed in t he elec tron ic cont ro l unit . The
front passenger frontal a irbag w ill also be turned
off if the capacitance measured by the system for
the front passenger seat equals that of an infant
of about one year of age in one of the chi ld seats
that was used to certify the Advanced Airbag Sys­
tem under Federa l Motor Vehicle Safety Standard
208 . The
PASSENGER AIR BAG OFF light comes
o n and stays on to tell you w hen the front Ad­
vanced Airbag Sys tem on t he passenger side has
been t urned
off ~ page 281 .
A WARNING
To reduce the ris k of injury when an airbag in­
flates, always wea r safe ty belts p rope rly.
- If you are un res tra ined, le a ning forwar d, si t­
ting sideways or out of posi tion in any way,
your ris k of injury is much higher.
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Airbag syste m
A WARNING
A child in a rearward-facing child seat instal­
led o n the front passenger seat will be ser i­
ously injured and can be k ille d if the front air­
bag in flate s - even with an Advanced Airbag
System.
- The inflating a irbag w ill hit the child seat or
infant carrier w ith great force and will
smash the ch ild seat and child against the
backrest, cente r arm rest, door or roof.
- Always install rear-facing child seats on the
rea r seat.
- If you must install a rearward fac ing ch ild
seat on the front passenger seat because of
exceptional c ircumstances and the
PASSEN­
GER AIR BAG OFF
light does not come on
and stay on, immediately insta ll the rear­
facing child seat in a rear seating position and have the airbag system inspected by
your Audi dealer.
A WARNING
-
-
Objects between you and the a irbag w ill in­
crease the risk of in jury in a crash by interfer­
ing w ith the way the airbag unfolds or by be­
ing pushed into you as the a irbag inflates.
- Never hold th ings in your hands or on your
lap when the vehicle is in use .
- Never transport items on or in the area of
the fron t passenger seat . Objects could
move into the area of the front airbags du r­
ing bra king or other sudden maneuve rs and
become dangerous projec tiles that c an
ca use serious pe rsonal injury if the a irbags
inflate.
- Never pl ace or attach accessor ies or o ther
objects (such as cup ho lders, te lephone
brackets, large, heavy or bulky objects) on
the doors, over or nea r the area marked
"AIRBAG" on the steering wheel, instru­
ment pane l, seat backrests or between
those areas and yourself. These objects could cause injury in a crash, especially
when the airbags infla te.
- Never recline the front passenger's seat to
transport objects . Items can also move into
the a rea of the side airbag o r the front a ir-
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bag du ring brak ing o r in a sudden maneu­
ver. Objects near the airbags can become pro jecti les and cause injury, part icularly
when the seat is reclined .
- Never p lace or transport objects on the
front passenger seat. Objects on the front passenger seat could cause the capacitive
sensor in the seat to signal to ai rbag system
that the seat is occ upied by a person when it
in fact is no t, or that the pe rson on the seat
is he avie r th an he or she act ually is. The
change in electric capacitan ce beca use of
such objects can cause the passenge r front
airbag to be turne d on when it should be
off, or can cause the airbag to work in a way
that is different from the way it would have
wo rked without objects on the seat.
- Always make sure that there is noth ing on
the front passenger seat that will cause the
capacitive passenger detection system in
the sea t to signal to the Airbag System that
the seat is occup ied by a person when it is
not, or to signal that it is occupied by some­
one who is heavier th an the person actu ally
si tting on the sea t. The presence of an o b­
ject could ca use the passenger front air bag
to be turned on when it should be off, or
could cause the airbag to work in a way that is diffe rent from the way it would have
worked without the object on the seat.
A WARNING
The fine dust created when airbags deploy can
cause breathing prob lems for people with a
h istory of asthma or othe r breath ing cond i­
tions .
- To reduce the r isk of breathing p roblems ,
those wi th asthma o r other respiratory con­
ditions sho uld get fresh a ir rig ht away by
getting out of the vehi cle or opening win­
dows or doors.
- If you are in a co llision in which airbags de­
ploy, w ash yo ur hands and f ace with m ild
soap and water be fore eating.
- Be ca refu l not to get the dust into your eyes,
or into any cuts or scratches.
- If the residue sho uld get into your eyes,
flush them w ith wate r.

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Monitoring the
Advanced Airbag System
Airbag monitoring indicator light
Two separate indicators monitor the fun ction of
the Advanced Airbag System : the
El ligh t and
t he
PASSENGER AIR BAG OFF light.
The Advanced Airbag System as we ll as the side
a ir bags and side curta in airbags with ejec tion
m it iga tion feat ures ( incl udi ng t he e lectro nic con­
tro l unit, sensors and system wiring) are all
monitored co nti nu ously to ma ke sure that they
are funct ion ing prope rly whenever the ignition is
on. Every t ime yo u turn on the ignition, the air ­
bag system ind icator
light E,lwill come on for a
few seconds (function check).
The system mu st be inspected when the
indicator light
E,I:
- does not come on when the ignit ion is switched
on,
- does not go out a few seconds after you have
switched on the ign ition, o r
- comes on w hile driving.
If an airbag sys tem malf unct ion is de tected, the
indicator light w ill come on to serve as a co nstant
rem inder to have the system inspected immedi­
ately .
If a mal function occurs t hat turns the front air ­
bag on the passenger si de
off, the PASSENGER
AIR BAG OFF
light will come on and stay on
whenever the ignit io n is on.
A WARNING
An airbag system that is not funct ion ing prop­
er ly cannot provide supplemental p rotection
in a frontal crash .
- If the airbag indicator light¢
page 26
comes when the vehicle is be ing used, have
the sys te m inspect ed immed iate ly by yo ur
au tho riz ed Au di dealer.
It is possible that
t h e air bag will in flate w hen it i s n ot su p­
p osed to, o r will not infla te whe n it s hou ld.
Airbag system
PASSENGER AIR BAG OFF light
Fi g. 239 Center con so le : p asse nger a irbag off wa rning
light
T he PASSENGER AIR BAG OFF lig ht is loc ated in
t h e cente r of the instrume nt
panel ¢ fig. 239.
T he PASSENGER AIR BAG OFF light w ill come o n
and st ay on to te ll yo u when the front Adv anced
Airbag on the passenger sid e has bee n turned o ff
by the e lec tronic contro l unit. If the b ulb for the
PASSENGER AIR BAG OFF light bur ns o ut, the
airbag indicato r light
El will come on to signal a
malfunction in the Advanced A irbag System. Al ­
t h ough the burned-out bu lb w ill not change the
way the front passenger's fronta l airbag works, it
will no longer be possible to use the
PASSENGER
AIR BAG OFF
light to ma ke sure that the a irbag
o n/off status is cor rec t for the oc cupan t on the
front pas senge r seat. Have the air bag system in­
spe cted imme dia tely by your au thori zed A udi
dealer.
The PASSENGER AIR BAG OFF light will blink
for about 5 seconds when:
- the ignition is sw itched on and
- the capacit ive passenger detection system,
which switches the front seat passenger 's fron­
t al Advanced Airbag on and
off, detects a
change i n the status of the front passenger
seat.
As soon as the
PASSENGER AIR BAG OFF light
stops blinking, always ma ke sure that the a irbag
status (on or off) as shown by the
PASSENGER
AIR BAG OFF
l ight is p roper for the age, si ze and
ele ctri cal c ap aci tance of the pe rso n oc cupying
t h e front passenger sea t. A lways make s ure that
the safety be lt fo r the front passe nger seat is
prope rly faste ned.
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action is entered in your Audi Warranty &
Maintenance booklet under
AIRBAG RE­
PLACEMENT RECORD.
- Applies to plug-in hybrid* vehicles: In the
event of a collision where the airbags de­
ploy, the electrical connection to the high
voltage battery is automatically disconnect­
ed. This prevents a short c ircuit.
@) For the sake of the environment
Undeployed airbag modules and pretension­
ers might be classified as Perchlorate 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
miliar with these requirements and we recom­
mend that you have your 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-rim
combinations not approved by Audi, lowering the
vehicle, changing the stiffness of the suspension, including the springs , suspension struts, shock
absorbers etc. can change the forces that are
measured by the airbag sensors and sent to the
electronic control 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 which it would not deploy if
the changes had not been made. Other kinds of
changes may reduce the force levels measured by
the sensors and prevent the airbag from deploy­
ing when it should.
A WARNING
Changing the vehicle's suspension including
use of unapproved tire-rim combinations can
change Advanced Airbag performance and in-
.
Airbag system
crease the risk of serious personal injury in a
crash.
- Never install suspension components that
do not have the same performance charac­
teristics as the components originally instal­ led on your vehicle.
- Never use tire-rim combinations that have
not been approved by Audi.
Knee airbags
Description of knee airbags
Applies to: vehicles with knee airbags
The knee airbag system can provide supplemen­
tal protection to properly restrained front seat
occupants.
Fig. 240 Driver 's knee airbag
The driver knee airbag is in the instrument panel
underneath the steering
wheel¢ fig. 240, the
airbag for the passenger is at about the same
height in the instrument panel underneath the
glove compartment.
The knee airbag offers additional protection to
the driver's and passenger's knees and upper and
lower thigh areas and supplements the protec­
t ion provided by the safety belts.
If the front airbags deploy, the knee airbags also
deploy in frontal collisions when the deployment
threshold stored in the control unit is met
¢ page 2 79, More important things to know
about front airbags .
In addition to their normal safety function, safe­
ty belts help keep the driver or front passenger in
posit ion in a frontal collision so that the airbags
can provide supplemental protection .
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Airbag syste m
can be used with properly insta lled child re­
straints. Please be sure to read the important in ­
formation and warnings whenever using a child
restraint in a veh icle: Safety belts
c> page 260,
Airbag system c> page 269, Ch ild safety
c> page294 .
The s ide ai rb ag sy stem basic ally con sists of:
- the e lectron ic co ntrol mod ule and externa l side
impact sensors
- th e two airbags loca ted in t he sides of t he front
backrests and the two airbags* located in the
rear back rest
- th e a irbag wa rn ing light in the inst rument cl us-
ter.
The a irbag system is monito red elect ronically to
make certa in that it is funct ioning prope rly at all
t imes. Ea ch time you sw itch on the ign ition, the
airbag system indicato r light will come on for a
few seconds (self diagnostics) .
The s ide a irba g system supplements the safety
be lts and can help to reduce the risk of injury to
the dr iver's, front and rear* passenger 's upper
torso on the side of the vehicle t hat is struck in a
side co llision . The airbag dep loys only in side im ­
pacts and on ly when the ve hicle acceleration reg­
is tered by the control unit is h igh enough . If this
rate is below the reference value programmed in ­
to the control un it, the s ide a irbags w ill not be
tr iggered , even thoug h the ca r may be bad ly
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 possib le ang le of impact , since
the circumstances wi ll vary considerably between
one co llision and another. Important factors in ­
clude, for example, the nature (hard or soft) of
the impacting object, the angle of impact, vehicle
speed , etc.
c> page 289, 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 p as­
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 overa ll occu­
pant restraint sys tem in your vehicle . Always re­
member that the s ide airbag system can only
288
help to protect you if you are wear ing you r 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
so c> page 260, General no tes.
It is important to remember that w hile the sup­
plementa l side airbag system is designed to re ­
duce the likelihood of ser ious injuries, other in ju­
ries, for example, swelling, bru is ing, friction
burns and m inor abras ions can also be assoc iated
with deployed side airbags . Remember too, s ide
a irbags w ill dep loy only once and only in certa in
ki nds of acc idents
-you r safety belts are a lways
t h ere to offer p rotect ion.
Vehicle damage, repair costs or even the lack of
vehicle damage are not necessar ily an ind ication
of over-se nsit ive or fa iled a irbag act ivat ion. In
some coll is ions, bo th front and side airbags may
i nflate. Remember too, tha t airbags w ill dep loy
on ly once and on ly in certain kinds of collisions
-
your safety be lts are always there to offer protec ­
tion in those accidents in which ai rbags are not
supposed to deploy or when they have already
deployed .
The side airbag system will n ot deplo y:
-when t he ignition is switched off
- in side co llisions when the a ccelera tion meas -
ured by the sensor is too low
- in fro nt-end coll is io ns
- in rea r-end co llisions
- in rollovers .
In some types of accidents the front airbags, side
curtain airbags and side a irbags may be triggered
together .
A WARNING
-Safety belts and the airbag system will only
provide protect ion when occupants are i n
the prope r sea ting pos it ion
c> page 289.
- If t he a irbag ind icator light c> page 26
comes w hen the veh icle is being used, have
the system inspe cted immedia tely by your
author ized A udi dealer. It is poss ib le that
the airbag will in flate when i t is not sup ­
posed to, or wi ll not inflate when it should .

Airbag system
-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 by being pushed into you as the a irbag in­
flates.
- 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 projectiles and cause injury
when the supplemental s ide airbag de­
ploys.
- Never carry any objects or pets in the de­
ployment space between them and the
airbags or allow chi ldren or other passen­
gers to travel in this posit ion.
- 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.
- T he 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 modu le must always
be repaired immediately by an authorized
Audi dealer.
-If children are seated improper ly, their risk
of injury increases in the case of an acc ident
¢ page 2 94, Child safety.
-Never attempt to modify any components of
the a irbag system in any way.
-In a side collision, side airbags w ill not func­
t ion properly if sensors cannot correctly
measure increasing air pressure inside the
290
doors when air escapes through larger, un­
closed openings in the door panel.
- Never drive with inte rior door trim panels
r emoved.
- Never dr ive when parts have been re­
moved from the inside door panel and the
openings they leave have not been proper­
l y 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
cove red or filled if additional speakers or
other equipment is installed in the inside
door panels .
- Always have work on the doors done by an
authorized Aud i dealer or qualified work­
shop .
Side curtain airbags
Description of side curtain airbags
Applies to: vehicles with side curtain airbags
The side curtain airbag sys tem can provide sup­
plemental protection to properly restrained oc­
cupants .
Fig. 24S Sid e curt ain air b ags , driver's s ide: s ide curt ain air­
bag location (example)
The side curtain airbags are located on both sides
of the inter ior above the front and rear side win­
dows ¢
fig. 245. They are identified by the word
"A IRBAG" on the windshie ld frame and the cen­
ter roof pillar.
The side curtain airbags contain features that
provide ejection mitigation to help prevent vehi-
cle occupants or parts of their bodies from being completely or partia lly ejected from the vehicle
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