2008 AUDI A4 belt

Seat belts 196The physical principles involved in a frontal collision are relatively
simple:
Both the moving vehicle and the passengers possess energy, which
is known as “kinetic energy” ⇒page 195, fig. 204. The amount of
“kinetic energy” depends on the speed of the vehicle and the weight
of the vehicle and passengers. The higher the speed and the greater
the weight, the more energy there is to be absorbed in an accident.
The most significant factor, however, is the speed of the vehicle. If
the speed doubles from 25 km/h to 50 km/h, for example, the kinetic
energy increases by a factor of four. Because these passengers are
not restrained by seat belts, the entire amount of kinetic energy has
to be absorbed at the point of impact ⇒fig. 205. This would result
in serious or potentially fatal injury.
Even at urban speeds of 30 km/h to 50 km/h, the forces acting on the
occupants in a collision can reach the equivalent of 1 ton (1000 kg)
or more. At greater speed these forces are even higher. A rule of
thumb: if the speed doubles, the forces increase by a factor of four.
Passengers who do not wear seat belts are not “attached” to the
vehicle. In a frontal collision they will continue to move forward at
the speed their car was travelling just before the impact.
What happens to passengers not wearing seat belts?
Passengers not wearing seat belts risk fatal injuries in the
event of an accident.In a frontal collision, unbelted passengers will be thrown forwards
and make violent contact with the steering wheel, dashboard, wind-
screen, etc ⇒fig. 206. Passengers not wearing their belts risk being
thrown out of the car, resulting in potentially fatal injuries.
The common belief that occupants can brace their weight with their
hands in a minor collision is false. Even at low speeds the forces
acting on the body in a collision are so great that it is not possible
to hold yourself in the seat.
Fig. 205 The vehicle
crashes against the
wall
Fig. 206 A driver not
wearing a seat belt can
be thrown forwardsFig. 207 A rear
passenger not wearing
a seat belt can be
thrown forwards
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Seat belts197
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Technical data It is also important for the rear passengers to wear seat belts, as
they could otherwise be thrown forwards violently in an accident.
Rear passengers who do not use seat belts endanger not only them-
selves but also the other occupants ⇒page 196, fig. 207.
How to wear seat belts properlyPutting on the three-point seat belts
Always fasten your seat belts before driving off.– Adjust the front seat and head restraint correctly before
putting on the seat belt ⇒page 73, “Seats and storage”.– To fasten the belt, take hold of the latch plate and pull it
slowly across your chest and lap ⇒.
– Insert the latch plate into the buckle for the appropriate
seat and push it down until it is securely locked with an
audible click ⇒fig. 209.
– Pull the belt to check that it is now securely fastened.
The three-point inertia reel belts are tensioned automatically. The
retractor system gives complete freedom of movement, as long as
the pull on the belt is slow. Hard braking locks the belt. The belt will
also lock when you accelerate, drive up or down a steep hill or in a
sharp curve.
WARNING
•
Always make certain that the belt is positioned properly
⇒fig. 208 – risk of injury ⇒page 197, “Adjusting the seat belts”.
•
The latch plate of the belt must always be engaged in the
correct buckle for that seat. Otherwise the belt will not be fully
effective and the danger of injury increases.
Adjusting the seat belts
Always position seat belts properly for maximum safety.
Fig. 208 Positioning of
head restraints and
seat beltsFig. 209 Driver's seat:
Belt buckle and latch
plate
Fig. 210 Adjusting
shoulder and lap belt
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Seat belts 198The height of the front seat on your vehicle can be adjusted in order
to match the position of the seat belt to your height.
WARNING
•
The diagonal part of the belt should never be positioned across
the neck, but roughly over the centre of the shoulder; it should fit
closely against the upper part of the body. The lap part of the belt
must be worn tightly across the hips, and not over the abdomen
⇒page 197, fig. 210. Pull the belt tight if necessary to take up any
slack.
•
Always make sure that belt is positioned properly. Incorrectly
worn seat belts can give rise to injuries even in a minor collision.
•
Seat belts worn too loose can result in injuries because they
allow excessive forward movement in a crash; the occupant will
be brought to a sudden stop by the belt webbing.
Wearing and adjusting the seat belts during pregnancy
To afford the best protection for the unborn child it is
important for the mother to wear the seat belt properly at
all times.
Women should always ensure they adjust the seat belt
correctly during pregnancy.
– Adjust the front seat and head restraint correctly before
putting on the seat belt ⇒page 73, “Seats and storage”.
– To fasten the belt, take hold of the latch plate and pull it
slowly down across your chest. Wear the lap portion of
the seat belt as low as possible over the hips so that there
is no pressure on the stomach ⇒fig. 211, ⇒.
– Insert the latch plate into the buckle for the appropriate
seat and push it down until it is securely locked with an
audible click ⇒page 197, fig. 209.
– Pull the belt to check that it is now securely fastened.
WARNING
During pregnancy, women should especially make sure to wear
the lap portion of the seat belt as low as possible across the hips
so that there is no pressure on the stomach.
Fig. 211 Positioning
seat belts during preg-
nancy
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Seat belts199
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Technical data
Applies to vehicles:Seat belt height adjustment
Seat belt height adjusters can be used to adjust the height
of the shoulder portion of the seat belt.– Take hold of the guide fitting and slide it up ⇒fig. 212 ,
or
–Compress the adjuster and slide the guide fitting
downwards .
– After adjusting, pull the shoulder belt sharply to check
that the catch on the guide fitting is engaged securely.
Note•
The shoulder portion of the seat belt must be positioned roughly
midway over the shoulder – it must never rest against the neck
⇒ in “Adjusting the seat belts” on page 197.
•
It is also possible to adjust the height of the front seats to obtain
the best position for the front seat belts.
Taking off the seat belts
The red button releases the belt from the buckle.– Press the red button in the seat belt buckle ⇒fig. 213.
The latch plate will spring out of the buckle.
– Guide the belt back by hand so that it is taken up by the
retractor.Belt tensionersHow the belt tensioners work
The seat belts for the driver and front passenger are
equipped with belt tensioners.The seat belts on the front seats are tensioned automatically in
frontal, side and rear-end impacts above a certain degree of
severity. This helps to reduce the forward motion of the occupants.
In a less severe accident, or in the event of a roll-over, the belt
tensioners are not activated.
Fig. 212 Belt height
adjustment for the
front seats: guide
fitting
A2
A1
A2
Fig. 213 The latch
plate of the belt
springs out of the
buckle
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Seat belts 200
WARNING
•
Any work on the tensioner system or removal and installation
of system components for other repairs must be performed by a
qualified workshop.
•
The belt tensioners can only be activated once. If they have
been activated at any time, the system must be replaced.Note
•
Some smoke may be released when the belt tensioners are acti-
vated. This does not mean there is a fire in the vehicle.
•
The relevant safety requirements must be observed when the
vehicle or components of the system are scrapped. Your authorised
Audi dealer is familiar with these regulations and will be pleased to
pass on the information to you.
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Airbag system201
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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
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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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