2008 AUDI A4 airbag

Airbag system201
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Airbag systemDescription of airbag systemGeneral notes on airbag system
The airbag is an integral part of the car's passive safety
system.In conjunction with the three-point seat belts, the airbag system
gives the front occupants additional protection for the head and
chest in the event of a severe frontal collision.
In a severe side collision the side airbags and the head-protection
airbags reduce the risk of injury to the occupants in the areas of the
body facing the impact ⇒.
In addition to their normal function of protecting the occupants in a
collision, the seat belts also hold them in a position where the
airbags can inflate properly and provide maximum protection.
The airbag system will only work with the ignition on. The airbag
system is monitored electronically; the airbag warning lamp indi-
cates whether the system is functioning properly.
The main parts of the airbag system are:•
the electronic monitoring system (control unit and sensors),
•
the two front airbags,
•
the front side airbags, the side airbags on the outer rear seats*
and the head-protection airbags,
•
the airbag warning lamp in the instrument cluster.
There is a fault in the airbag system if the warning
lamp
•
does not come on when the ignition is switched on,
•
does not go out about 4 seconds after the ignition is switched
on,
•
goes out and then comes on again after the ignition is switched
on,
•
comes on or flickers while the car is moving.
WARNING
•
The airbags are not a substitute for the seat belts; they are an
integral part of the car's overall passive safety system. The airbags
can only offer effective protection if the occupants are wearing
their seat belts. For this reason it is very important to wear the
seat belts at all times ⇒page 194, “Why is it so important to use
seat belts?”.
•
The seat belts and airbags can only provide maximum protec-
tion if the occupants are seated correctly ⇒page 73, “Seats and
storage”.
•
If you do not wear a seat belt, if you lean forward, or are not
seated correctly while the vehicle is in motion, you are at greater
risk of injury should the airbag system be triggered in an accident.
•
Components of the airbag system are located in various parts
of the vehicle. If repairs to other vehicle components make it
necessary to perform work on the airbag system or to remove or
install parts of the airbag system, this may cause damage to the
airbag system. As a result, the airbags may not inflate correctly or
may not be triggered at all in an accident situation. For this reason,
you should always have the work carried out by a qualified work-
shop.
•
If a fault should occur in the airbag system, have the system
checked immediately by a qualified workshop. Otherwise the
system may fail to trigger in an accident.
•
Do not attempt to modify components of the airbag system in
any way.
•
Never make any alterations to the front bumper or the body.
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Airbag system 202•
Do not remove the front seats.
•
The airbag system can only be activated once; if the airbag has
been triggered, the system must be replaced. Should the airbag
system or airbag modules have to be replaced, the qualified work-
shop carrying out the replacement will document all details in the
appropriate section of the Service Schedule.
•
If you sell the vehicle, please remember to pass on the
complete Service Wallet to the new owner. If any of the airbags
have been deactivated, it is important that the new owner is also
given the relevant documents.
•
The relevant safety requirements must be observed when the
vehicle or components of the airbag or belt tensioner systems are
scrapped.
•
In an accident in which one or more airbags are triggered the
alternator and the starter are - for safety reasons - both discon-
nected from the battery via a pyrotechnic circuit breaker.
−Any repairs to the pyrotechnic circuit breaker must always
be performed by a qualified workshop (accident risk).
−The relevant safety requirements must be observed when
the vehicle or the circuit breaker are scrapped.
When are the airbags triggered?
The airbag system is triggered in collisions with a severe
impact.The airbag system is designed so that the airbags for the driver and
front passenger are triggered in a severe frontal collision.
In severe side collisions the side airbags on the impact side of the
vehicle are triggered together with the head-protection airbag.
The front airbags, side airbags and one of the head-protection
airbags may be triggered together in certain types of accident.The airbag system is not triggered in minor frontal or side collisions,
or in rear collisions or if the car overturns. In these situations the
occupants are protected by wearing the seat belts.
Factors determining the triggering response
It is not possible to define the exact triggering response of the
airbag system in all possible situations, since the circumstances in
different types of accident will vary considerably. Important factors
include, for example, the nature (hard or soft) of the object which
the car hits, the angle of impact, vehicle speed and so on.
Whether the airbags are triggered depends primarily on the vehicle
deceleration rate resulting from the collision. By processing the
signals from the sensors located in the vehicle, the electronic
control unit is immediately able to evaluate the severity of the colli-
sion and activate the restraint systems accordingly. If the decelera-
tion rate is below the predefined reference value in the control unit
the airbags will not be triggered, even though the accident may
cause extensive damage to the car.
Note
The airbag releases a fine dust when it inflates. This is quite normal
and does not mean there is a fire in the vehicle.
WARNING (continued)
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Airbag system203
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Front airbagsDescription of front airbags
The airbag system is not a substitute for the seat belts.The front airbag for the driver is located in the padded hub of the
steering wheel ⇒fig. 214. The front airbag for the front passenger
is in the dashboard above the glove box ⇒fig. 215. The locations of
the airbags are marked with the word “AIRBAG”.
In conjunction with the three-point seat belts, the front airbags give
additional head and chest protection for the driver and front
passenger in the event of a severe frontal collision ⇒ in “Impor-
tant safety notes on the front airbag system” on page 204.
How the front airbags work
When fully inflated, the airbags reduce the risk of head or
chest injury.The airbag system is designed so that the airbags for the driver and
front passenger are triggered in a severe frontal collision.
In certain types of accident the front airbags, side airbags and one
of the head-protection airbags may be triggered together.
When the system is triggered, the airbags fill with a propellant gas
and open out in front of the driver and front passenger ⇒fig. 216.
In order to provide the desired extra protection in an accident, the
airbags have to inflate extremely rapidly (within fractions of a
second). The fully deployed airbags cushion the forwards move-
ment of the front occupants and help to reduce the risk of injury to
the head and the upper part of the body.
Special openings in the airbag allow the gas to escape at a
controlled rate to restrain the forward movement of the occupant's
head and torso. Once the impact has been absorbed, the airbag
deflates sufficiently for the front occupants to see forward.
Fig. 214 Driver's
airbag in steering
wheelFig. 215 Front
passenger's airbag in
dashboard
Fig. 216 Front airbags
in inflated condition
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Airbag system 204Important safety notes on the front airbag system
There are a number of safety points concerning the airbag
system which you should remember. This will help to
reduce the risk of injury in an accident.
WARNING
•
It is important for the driver and front passenger to maintain a
distance of at least 25 cm from the steering wheel or dashboard
⇒fig. 217. The airbag system will not be able to give the required
protection if you sit too close to the steering wheel or dashboard.
There is also a risk of injury if the airbags are inflated. The front
seats and head restraints must always be positioned correctly for
the height of the occupant.
•
If you do not wear a seat belt, if you lean forward or to the side,
or are not seated correctly while the vehicle is in motion, you are
at greater risk of injury. Should the airbag system be triggered in
an accident there is an even greater risk of injury.
•
Never let a child travel on the front seat without an appropriate
restraint system. If the airbag is triggered in an accident, the child
could sustain serious or fatal injuries ⇒page 210, “Child safety”.
•
Never install a rearward-facing child safety seat on the front
passenger's seat unless the front passenger's airbag has been deactivated. However, if you have no alternative but to use a rear-
ward-facing child seat on the front passenger's seat, the front
passenger's airbag must be deactivated beforehand by means of
the key-operated switch* ⇒page 208. Failure to observe this
precaution could result in serious or potentially fatal injury.
•
Occupants sitting in the front of the car must never carry any
objects or pets in the space between them and the airbags, or
allow children or other passengers to travel in this position.
•
Do not cover or stick anything on the steering wheel hub or the
soft plastic surface of the airbag unit on the passenger's side of
the dashboard, and do not obstruct or modify them in any way.
These parts should only be cleaned with a dry cloth (or with a
cloth moistened with plain water). It is also important not to
attach any objects such as cup holders or telephone mountings to
the surfaces covering the airbag units.
•
Any work on the airbag system or removal and installation of
the airbag components for other repairs (such as repairs to the
steering wheel or removal of seats) must be performed by a qual-
ified workshop.Note
If necessary, you can deactivate the front passenger's airbag by
means of the key-operated switch* ⇒page 208.
Fig. 217 Minimum
distance from steering
wheel
WARNING (continued)
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Airbag system205
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Side airbagsDescription of side airbags
The airbag system is not a substitute for the seat belts.The side airbags are located in the backrest padding of the front
seats ⇒fig. 218. The locations of the airbags are marked with the
word “AIRBAG”.
In conjunction with the three-point seat belts, the side airbags give
the occupants additional protection for the whole upper part of the
body (i.e. the chest, stomach and pelvis) in the event of a severe side
collision ⇒ in “Important safety notes on the side airbag system”
on page 206.
In a side collision the side airbags reduce the risk of injury to the
areas of the body facing the impact.
If the side airbags are activated, the head-protection airbags (side-
guard system) are always triggered at the same time for additional
protection on the side of the vehicle facing the impact
⇒page 207.
How the side airbags work
When fully inflated, the side airbags reduce the risk of
injuries to the upper part of the body.In certain types of side collisions the side airbags (front and rear*)
are triggered on the impact side of the vehicle ⇒fig. 219.
The front airbags, side airbags and the head-protection airbag may
be triggered together in certain types of accident.
When the system is triggered, the airbag is filled with propellant
gas.
In order to provide the desired extra protection in an accident, the
airbags have to inflate extremely rapidly (within fractions of a
second). The airbag releases a fine dust when it inflates. This is quite
normal and does not mean there is a fire in the vehicle.
When fully deployed, the airbags cushion the impact for the occu-
pants and help to reduce the risk of injury to the whole upper part
of the body (i.e. the chest, stomach and pelvis) on the side facing the
door.
Fig. 218 Location of
side airbag in driver's
seat
Fig. 219 Side airbags
in inflated condition
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Airbag system 206Important safety notes on the side airbag system
There are a number of safety points concerning the airbag
system which you should remember. This will help to
reduce the risk of injury in an accident.
WARNING
•
If you do not wear a seat belt, if you lean forward, or are not
seated correctly while the vehicle is in motion, you are at greater
risk of injury should the side airbags on the front seats or the outer
rear seats* be triggered in an accident. This applies particularly to
children if they are not properly protected by a child restraint
system ⇒page 212, “Important notes on side airbags and child
safety”.
•
If children are not seated correctly, they are at greater risk of
injury in an accident. This is particularly the case if the child is
travelling on the front passenger's seat and the airbag system is
triggered. This could result in serious or potentially fatal injury
⇒page 210, “Child safety”.
•
It is also important not to attach any accessories (such as cup
holders) to the doors. This would impair the protection offered by
the side airbags (front and rear*).
•
The sensors for the airbags are located in the front doors. You
must therefore not make any modifications to the doors or door
trim (e.g. retrofitting loudspeakers), as this could impair the func-
tion of the side airbags. Any damage to the front doors could lead
to faults in the system. Repairs or any other work on the front
doors must therefore always be carried out by a qualified work-
shop.
•
The built-in coat hooks should only be used for lightweight
clothing. Do not leave any heavy or sharp-edged objects in the
pockets.
•
Do not apply excessive force to the sides of the backrests (such
as hard knocks or kicks), as this could damage parts of the system.
The side airbags could then fail to operate when required.
•
If you intend to fit protective covers over the seats, these must
be of the specific type approved for use on Audi seats with side
airbags. Conventional seat covers would obstruct the side airbag
when it inflates out of the backrest, and seriously reduce the
airbag's effectiveness.
•
Any damage to the original seat upholstery or around the
seams of the side airbag units must be repaired immediately by a
qualified workshop.
•
Any work involving the side airbag system or removal and
installation of the airbag components for other repairs (such as
repairs to the seats) must always be performed by a qualified
workshop. Otherwise the airbag system may fail to work
properly.WARNING (continued)
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Airbag system207
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Head-protection airbags (sideguard)Description of head-protection airbags
The head-protection airbags work together with the side
airbag system to give extra protection in a side impact.The head-protection airbags are located above the doors on the left
and right sides of the vehicle ⇒page 207, fig. 220. The locations of
the airbags are marked with the word “AIRBAG”.
In conjunction with the three-point seat belts and side airbags, the
head-protection airbags give the occupants additional protection
against head and neck injuries in a severe side collision ⇒ in
“Important safety notes on the head-protection airbags” on
page 208.
Together with other design features (including cross-braces in the
seats and the overall strength of the body structure), the sideguard
system offers an effective further improvement to occupant protec-
tion in side impacts.
How the head-protection airbags work
When fully inflated, the airbags reduce the risk of head or
chest injury in a side collision.In certain types of side collisions the head-protection airbag is trig-
gered together with the side airbag on the impact side of the vehicle
⇒fig. 221.
When the system is triggered, the airbag fills with a propellant gas
and covers the entire area in front of the side windows, including
the door pillars. In this way the system is able to protect both the
front and the rear occupants on the side of the vehicle where the
impact occurs. The head-protection airbag inflates to soften the
impact if an occupant strikes parts of the interior or objects outside
the vehicle with their head. By reducing the head impact and
restraining uncontrolled movement of the head, the airbag also
reduces the forces acting on the neck. In addition, since it covers the
front door pillar when fully inflated, the head-protection airbag also
gives extra protection if the car should collide with an obstacle at an
oblique angle.
The front airbags, side airbags and head-protection airbags may be
triggered together in certain types of accident.
In order to provide the desired extra protection in an accident, the
airbags have to inflate extremely rapidly (within fractions of a
Fig. 220 Location of
head-protection
airbags above the
doors
Fig. 221 Head-protec-
tion airbags in inflated
condition
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Airbag system 208second). The airbag releases a fine dust when it inflates. This is quite
normal and does not mean there is a fire in the vehicle.Important safety notes on the head-protection airbags
There are a number of safety points concerning the airbag
system which you should remember. This will help to
reduce the risk of injury in an accident.
WARNING
•
It is important to ensure that the area around the openings for
the head-protection airbags remains unobstructed at all times, so
that the airbags can inflate properly if needed.
•
The built-in coat hooks should only be used for lightweight
clothing. Do not leave any heavy or sharp-edged objects in the
pockets. When using the coat hooks, do not hang the clothes on
coat hangers.
•
The space between the passengers and the head-protection
airbags must never be occupied by children, other passengers or
pets. Passengers should never lean out or put a hand or arm out of
the window while the vehicle is in motion.
•
Do not move the sun visors out to cover the side windows if
there is anything attached to them (such as pens or a remote
control for the garage door). These objects could cause injury if the
head-protection airbag is triggered.
•
The sensors for the airbags are located in the front doors. You
must therefore not make any modifications to the doors or door
trim (e.g. retrofitting loudspeakers), as this could impair the func-
tion of the side airbags. Any damage to the front doors could lead
to faults in the system. Repairs or any other work on the front
doors must therefore always be carried out by a qualified work-
shop.
•
Where sun blinds are fitted on the rear doors, these must not
obstruct or impair the airbags in any way.
•
If unsuitable accessories are installed near the head-protection
airbag, the protection afforded by the airbag can be seriously
impaired if the system is triggered. When the head-protection
airbag opens, parts of these accessories could be thrown into the
vehicle and injure passengers ⇒page 277.
•
Any work involving the head-protection airbags, or removal
and installation of the airbag components for other repairs (such
as repairs to the roof liner), must always be performed by a quali-
fied workshop. Otherwise the airbag system may fail to work
properly.
Applies to vehicles: with key-operated switch for front passenger's airbagDeactivating the front passenger's airbag via the key-operated switchIf an airbag has been deactivated, it should be reactivated
as soon as possible so that it can continue to give the
required protection.
WARNING (continued)
Fig. 222 Key-operated
switch in glove box for
deactivating front
passenger's airbag
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