2020 AUDI A3 sensor

8V2012721BK
Airbag system

the seat may prevent the Advanced Airbag Sys-
tem for the front passenger seat from doing its
job ina crash.
The front Advanced Airbag System consists
of the following:
— Crash sensors in the front of the vehicle that
measure vehicle acceleration/deceleration to
provide information to the Advanced Airbag
System about the severity of the crash.
— An electronic control unit, with integrated
crash sensors for front and side impacts. The
control unit “decides” whether to fire the front
airbags based on the information received from
the crash sensors. The control unit also “de-
cides” whether the safety belt pretensioners
should be activated.
— An Advanced Airbag with gas generator for the
driver inside the steering wheel hub.
— An Advanced Airbag with gas generator inside
the instrument panel for the front passenger.
— A capacitive passenger detection system under-
neath the front passenger seat cover. This sys-
tem measures the electrical capacitance of the
person in the seat. The information registered
is sent continuously to the electronic control
unit to regulate deployment of the front Ad-
vanced Airbag on the passenger side.
— An airbag monitoring system and indicator
light in the instrument cluster > page 265.
—Asensor in each front seat registers the dis-
tance between the respective seat and the
steering wheel or instrument panel. The infor-
mation registered is sent continuously to the
electronic control unit to regulate deployment
of the front Advanced Airbags.
— The PASSENGER AIR BAG OFF light comes on
and stays on in the center of the instrument
panel > page 304 and tells you when the front
Advanced Airbag on the passenger side has
been turned off.
—Asensor 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
transmits this information to the electronic
control unit.


ZA 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 prevent the
Advanced Airbag System from functioning
properly.
— Repairs to the front passenger seat must be
performed by qualified and properly trained
workshop personnel.
— Never remove the front passenger or driver
seat from the vehicle.
— Never remove the upholstery from the front
Passenger Seat.
— Never disassemble or remove parts from the
seat or disconnect wires from it.
— Never carry sharp objects in your pockets or
put them on the seat. The capacitive passen-
ger detection mat in the front passenger
seat will not function properly if it is punc-
tured.
— Never carry things on your lap or carry ob-
jects on the front passenger seat. Such ob-
jects can
influence the capacitance regis-
tered by the capacitive passenger detection
system, so that incorrect information is pro-
vided to the airbag control unit.
— Never store items under the front passenger
seat. Parts of the Advanced Airbag System
under the passenger seat could be dam-
aged, preventing them and the airbag sys-
tem from working properly.
— Never place 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 Airbag
System from recognizing child restraints 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 install any child restraint system on
this seat.
— Never use cushions, pillows, blankets, or
similar items on the front passenger seat.
The additional layers prevent the capacitive

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Airbag system


passenger detection system from accurately
measuring the capacitance of the child 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 device, 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. Such
devices can influence the capacitance regis-
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 child restraint, make
certain that the PASSENGER AIR BAG OFF
light comes on and stays on whenever the
child restraint is installed on the front pas-
senger seat.
— If the PASSENGER AIR BAG OFF light does
not come on and stay on, immediately in-
stall child restraint in a rear seating position
and have the airbag system inspected by
your Audi dealer.


Z\ 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, deacti-
vate the passenger frontal airbag. If this
happens, the PASSENGER AIR BAG OFF
light will come on and stay on together with
the airbag indicator light Ea in the instru-
ment cluster.
— If liquid is pooled on the seat, but has not
soaked in, this may also keep the airbag sys-
tem from working properly and cause the
passenger frontal airbag to be enabled
(turned on), even though there is a properly
installed child restraint system on the seat.
Wet towels or other wet things on the seat

cushion can have the same effect. If the
front passenger frontal airbag is turned on,
the PASSENGER AIR BAG OFF light will turn
off.

How the Advanced Airbag System
components work together
The front Advanced Airbag System and the side
airbags supplement the protection offered by the
front three-point safety belts and the adjustable
head restraints* to help reduce the risk of injury
in a wide range of accident and crash situations.
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 deceleration measured by the crash
sensors and registered by the electronic control
unit. Crash severity depends on speed and decel-
eration 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 airbag will be
turned off if the electrical capacitance measured
by the capacitive passenger detection system on
the front passenger seat is less than the amount
programmed in the electronic control unit. The
front passenger frontal airbag will 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 child seats
that was used to certify the Advanced Airbag Sys-
tem under Federal Motor Vehicle Safety Standard
208. The PASSENGER AIR BAG OFF light comes
on and stays on to tell you when the front Ad-
vanced Airbag System on the passenger side has
been turned off > page 265.

ZA WARNING
To reduce the risk of injury when an airbag in-
flates, always wear safety belts properly.
— If you are unrestrained, leaning forward, sit-
ting sideways or out of position in any way,
your risk of injury is much higher.
— You will also receive serious injuries and

could even be killed if you are up against the


262

Airbag system


smash the child seat and child against the
backrest, center armrest, door or roof.
— Always install rear-facing child seats on the
rear seat.
— If you must install a rearward facing child
seat on the front passenger seat because of
exceptional circumstances and the PASSEN-
GER AIR BAG OFF light does not come on
and stay on, immediately install the rear-
facing child seat in a rear seating position
and have the airbag system inspected by
your Audi dealer.


ZA WARNING
Objects between you and the airbag will in-
crease the risk of injury in a crash by interfer-
ing with the way the airbag unfolds or by be-
ing 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 dur-
ing braking or other sudden maneuvers and
become dangerous projectiles 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, especially 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 air-
bag during braking or in a sudden maneuver.
Objects near the airbags can become projec-
tiles and cause injury, particularly when the
seat is reclined.
— Never place or transport objects on the front
passenger seat. Objects on the front passen-
ger seat could cause the capacitive sensor in
the seat to signal to airbag system that the
seat is occupied by a person when it in fact is
not, or that the person on the seat is heavier
than he or she actually is. The change in
electric capacitance because of such objects
can cause the passenger front airbag to be
turned on when it should be off, or can
cause the airbag to work in a way that is dif-
ferent from the way it would have worked
without objects on the seat.
— Always make sure that there is nothing on
the front passenger seat that will cause the
capacitive passenger detection system in
the seat to signal to the Airbag System that
the seat is occupied by a person when it is
not, or to signal that it is occupied by some-
one who is heavier than the person actually
sitting on the seat. The presence of an ob-
ject could cause the passenger front airbag
to be turned on when it should be off, or
could cause the airbag to work in a way that
is different from the way it would have
worked without the object on the seat.


ZA\ WARNING
The fine dust created when airbags deploy can
cause breathing problems for people with a
history of asthma or other breathing condi-
tions.
—To reduce the risk of breathing problems,
those with asthma or other respiratory con-
ditions should get fresh air right away by
getting out of the vehicle or opening win-
dows or doors.
— If you are in a collision in which airbags de-
ploy, wash your hands and face with mild
soap and water before eating.
— Be careful not to get the dust into your eyes,
or into any cuts or scratches.
— If the residue should get into your eyes,
flush them with water.


264

8V2012721BK
Airbag system

Monitoring the
Advanced Airbag System

‘oring indicator light
Two separate indicators monitor the function of
the Advanced Airbag System: the ka light and
the PASSENGER AIR BAG OFF light.
The Advanced Airbag System as well as the side
airbags and side curtain airbags with ejection
mitigation features (including the electronic con-
trol unit, sensors and system wiring) are all
monitored continuously to make sure that they
are functioning properly whenever the ignition is
on. Every time you turn on the ignition, the air-
bag system indicator light ka will come on fora
few seconds (function check).
The system must be inspected when the
indicator light Ba:
— does not come on when the ignition is switched
on,
— does not go out a few seconds after you have
switched on the ignition, or
— comes on while driving.
If an airbag system malfunction is detected, the
indicator light will come on to serve as a constant
reminder to have the system inspected immedi-
ately.
If a malfunction occurs that turns the front air-
bag on the passenger side off, the PASSENGER
AIR BAG OFF light will come on and stay on
whenever the ignition is on.

ZA\ WARNING
An airbag system that is not functioning prop-
erly cannot provide supplemental protection
in a frontal crash.
- If the airbag indicator light > page 238
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 sup-
posed to, or will not inflate when it should.

PASSENGER AIR BAG OFF light


B8V-0215

Fig. 218 Center console: passenger airbag off warning
light
The PASSENGER AIR BAG OFF light is located in
the center of the instrument panel > fig. 218.
The PASSENGER AIR BAG OFF light will come on
and stay on to tell you when the front Advanced
Airbag on the passenger side has been turned off
by the electronic control unit. If the bulb for the
PASSENGER AIR BAG OFF light burns out, the
airbag indicator light 2 will come on to signal a
malfunction in the Advanced Airbag System. Al-
though the burned-out bulb will not change the
way the front passenger's frontal airbag works, it
will no longer be possible to use the PASSENGER
AIR BAG OFF light to make sure that the airbag
on/off status is correct for the occupant on the
front passenger seat. Have the airbag system in-
spected immediately by your authorized Audi
dealer.
The PASSENGER AIR BAG OFF light will blink
for about 5 seconds when:
— the ignition is switched on and
— the capacitive passenger detection system,
which switches the front seat passenger's fron-
tal Advanced Airbag on and off, detects a
change in the status of the front passenger
seat.
As soon as the PASSENGER AIR BAG OFF light
stops blinking, always make sure that the airbag
status
(on or off) as shown by the PASSENGER
AIR BAG OFF light is proper for the age, size and
electrical capacitance of the person occupying
the front passenger seat. Always make sure that
the safety belt for the front passenger seat is
properly fastened.
265

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Airbag system


entered in your Audi Warranty & Mainte-
nance booklet under AIRBAG REPLACEMENT
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 circuit.
Other things that can affect Advanced
ONY em ace lie
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.

ZX, 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 personal injury ina
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
Pregl) aCe ola ACLs eh)
Applies to: vehicles with knee airbags
The knee airbag system can provide supplemen-
tal protection to properly restrained front seat
occupants.

Fig. 219 Driver's knee airbag
The driver knee airbag is in the instrument panel
underneath the steering wheel > fig. 219, 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-
tion 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 263, 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
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 overall 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 al-
ways wear your safety belt, not just because the
law requires you to do so > page 245, General
notes.
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Airbag system

— the electronic control module and external side
impact sensors
— the two airbags located in the sides of the front
backrests and the two airbags* located in the
rear backrest
— the airbag warning light in the instrument clus-
ter.
The airbag system is monitored electronically to
make certain that it is functioning properly at all
times. Each time you switch on the ignition, 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* passenger's upper
torso on the side of the vehicle that is struck ina
side collision. The airbag deploys only in side im-
pacts and only 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 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 pos-
sible to define an airbag triggering 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. > page 273, Important safety in-
structions on the side airbag system.
Aside from their normal safety function, safety
belts work to help keep the driver or front pas-
senger in position in the event of a side collision
so that the side airbags can provide protection.
The airbag system is not a substitute for your
safety belt. Rather, it is part of the overall occu-
pant restraint system in your vehicle. Always re-
member that the side airbag system can only
help to protect you if you are wearing your safety
belt and wearing it properly. This is another rea-
son why you should always wear your safety
belts, not just because the law requires you to do
so > page 245, General notes.
It is important to remember that while the sup-
plemental side airbag system is designed to re-
272
duce the likelihood of serious injuries, other inju-
ries, for example, swelling, bruising, friction
burns and minor abrasions can also be associated
with deployed side airbags. Remember too, side
airbags will deploy only once and only in certain
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 indication
of over-sensitive or failed airbag activation. In
some collisions, both front and side airbags may
inflate. Remember too, that airbags will deploy
only once and only in certain kinds of collisions -
your safety belts 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 switched off
— in side collisions when the acceleration meas-
ured 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.

ZA WARNING
— Safety belts and the airbag system will only
provide protection when occupants are in
the proper seating position > page 273.
- If the airbag indicator light > page 238
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 sup-
posed to, or will 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 airbag 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 side airbag de-
ploys.
— Never carry any objects or pets in the de-
ployment space between them and the air-
bags or allow children or other passengers
to travel in this position.
— Always use the built-in coat hooks only for
lightweight clothing. Never leave any heavy
or sharp-edged objects in the pockets that
may interfere with side airbag deployment
and can cause personal injury in an accident.
— Always prevent the side airbags from being
damaged by heavy objects knocking against
or hitting the sides of the seatbacks.
— The airbag system can only be triggered
once. If the airbag has been triggered, the
system must be replaced by an authorized
Audi dealership.
— Damage (cracks, deep scratches etc.) to the
original seat covers or to the seam in the
area of the side airbag module must always
be repaired immediately by an authorized
Audi dealer.
— If children are seated improperly, their risk
of injury increases in the case of an accident
= page 278, Child safety.
— Never attempt to modify any components of
the airbag system in any way.
— Ina side collision, side airbags will not func-
tion properly if sensors cannot correctly
measure increasing air pressure inside the

274
doors when air escapes through larger, un-
closed 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 open-
ings 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.
— Always have work on the doors done by an
authorized Audi dealer or qualified work-
shop.

Side curtain airbags
Description of side curtain airbags
Applies to: vehicles with side curtain airbags
The side curtain airbag system can provide sup-
plemental protection to properly restrained oc-
cupants.
10 rn
2 3
ro a

Fig. 224 A curtain airbags, driver's side: side curtain air-
bag location (example)
The side curtain airbags are located on both sides
of the interior above the front and rear side win-
dows > fig. 224. They are identified by the word
“AIRBAG” on the windshield 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 partially ejected from the vehicle >

8V2012721BK
Airbag system

interior in certain side impacts and vehicle roll-
overs.
The side curtain airbag system supplements the
safety belts and can help to reduce the risk of in-
jury for occupants’ heads and upper torso on the
side of the vehicle that is struck in a side colli-
sion. The side curtain airbag inflates in side im-
pacts and only 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 unit, the side curtain airbag will
not be triggered, even though the car may be
badly damaged as a result of the collision. It is
not possible 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 fac-
tors include, for example, the nature (hard or
soft) of the impacting object, the angle of im-
pact, vehicle speed, etc. > page 276, How side
curtain airbags work.
Aside
from their normal safety function, safety
belts work to help keep the driver or front pas-
senger in position in the event of a collision so
that the side curtain airbags can provide protec-
tion.
The airbag system is not a substitute for your
safety belt. Rather, it is part of the overall 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 another reason
why you should always wear your safety belts,
not just because the law requires you to do so
= page 245, 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 example, swelling, bruising, friction burns
and minor abrasions can also be associated with
these airbags upon deployment. Remember too,
these airbags will deploy only once and only in
certain kinds of accidents - your safety belts are
always there to offer protection.
The side curtain airbag system basically
consists of:
— The electronic control module and external side
impact sensors
— The side curtain airbags above the front and
rear side windows with ejection mitigation fea-
tures
— The airbag indicator light in the instrument
panel
The airbag system is monitored electronically to
make certain it is functioning properly at all
times. Each time you switch on the ignition, the
airbag system indicator light will come on for a
few seconds (self diagnostics).
The side curtain airbag is not activated:
— if the ignition is switched off,
— in side collisions when the acceleration meas-
ured by the sensor is too low,
—in rear-end collisions.

ZA\ WARNING
— Safety belts and the airbag system will only
provide protection when occupants are in
the proper seating position > page 54,
Front seats.
— If the airbag indicator light > page 238
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 sup-
posed to, or will not inflate when it should.


275