wheel AUDI A4 AVANT 2008 Owner's Guide

of safety restraint systems, the unrestrained occupant will slam
violently into the steering wheel, instrument panel, windshield, or
whatever else is in the
way=> fig . 169. This impact with the vehicle
interior has all the energy they had just before the crash.
Never rely on airbags alone for protection . Even when they dep loy,
airbags provide only additional protection . Airbags are not
supposed to deploy in all kinds of accidents . Although your Audi is
e quipped wi th airbags, all vehicle occupan ts , including the driver,
must wear safety belts correctly in order to minimize the risk of
severe injury or death in a crash .
Remember too, that airbags will deploy only once and that 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 . Unbelted occupants can also be thrown out of the
vehicle where even more severe or fatal injuries can occur.
It is also important for the rear passengers to wear safety belts
correctly . Unbelted passengers in the rear seats endanger not only
themselves but also the driver and other
passengers~ page 178,
fig. 170. In a frontal collision they will be thrown forward violently,
where they can hit and injure the driver and/or front seat
passenger. •
Safety first
Safety belts
Safety belts protect
People think it's possible to use the hands to brace the
body in a minor collision. It's simply not true!
&l
9 w a, a,
Fig. 171 Driver is
correctly restrained in
a sudden braking
maneuver
Safety belts used properly can make a big difference. Safety belts
help to keep passengers in their seats, gradually reduce energy
levels applied to the body in an accident, and help prevent the
uncontrolled movement that can cause serious injuries. In addition ,
safety belts reduce the danger of being thrown out of the vehicle .
Safety belts attach passengers to the car and give them the benefit
of being slowed down more gently or "softly" through the "give" in
the safety belts, crush zones and other safety features engineered
into today's vehicles. By "absorbing" the kinetic energy over a
longer period of time, the safety belts make the forces on the body
more "tolerable" and less likely to cause injury .
Although these examples are based on a frontal collision, safety belts can also substantially reduce the risk of injury in other kinds
of crashes. So, whether you're on a long trip or just going to the
corner store, a lways buckle up and make sure others do, too . Acci­
dent statistics show that vehicle occupants properly wearing safety
belts have a lower risk of being injured and a much better chance of
surviving an accident . Properly using safety belts also greatly .,,_
irechnical data

________________________________________________ A_ i_ r _b _a..: g:::- s..: y:.. s_ t_ e_ m __ .... ffllll
Airbag system
Important things to know
Importance of wearing safety belts and
sitting properly
Airbags are only supplemental restraints. For airbags to
do their job, occupants must always properly wear their
safety belts and be in a proper seating position.
For your safety and the safety of your passengers, before
driving off, always:
- Adjust the driver's seat and steering wheel properly
=> page 168,
-Adjust the front passenger's seat properly=> page 96,
-Wear safety belts properly=> page 180 ,
- Always properly use the proper child restraint to protect
children
=> page 210 .
In a col lision airbags must inflate within the blink of an eye and with
considerable force . The suppl emental airbags can caus e injuries if
t he driver or the front seat passenger is not seated properly. There ­
fore in order to help the airbag to do its job , it is important, both as
a driver and as a passenger to sit properly at a ll times.
By keeping room between your body and the steering wheel and the
front of the passenger compartment, the airbag can inflate fully and
completely and provide supplementa l protect ion in certain frontal
collisions => page 168, "Proper occupant seating positions" . For
detai ls on the operation of the seat adjustment
contro ls => page 97.
It's especially important that children are properly restrained
=> page 210.
Controls and equip­ ment Safety first Vehicle operation
There is a lot that the driver and the passengers can and must do to
help the individual safety features installed in your Audi work
together as a system .
Proper sea ting position is important so that the fron t airbag on the
driver side can do its job. If you have a physical impairment or
condition that prevents you from sitting properly on the driver seat
with the safety belt properly fastened and reaching the pedals, or if
you have concerns with regard to the function or operation of the
Advanced Airbag System, please contact your authorized Audi
dea ler or qualified workshop, or ca ll Audi Customer CARE at 1 -800-
822 -2834 for possible modifications to your vehicle.
When the airbag system deploys, a gas generator wi ll fill the
airbags , break open the padded covers, and inflate between the
steering whee l and the driver and between the instrument pane l
and the front passenger. The airbags will deflate immediately after
deployment so that the front occupants can see through the wind ­
shie ld again without interruption .
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 nothing should be in their way
when they deploy. Front airbags in combination with proper ly worn
safety belts slow down and limit the occupant's forward movement .
Together they help to prevent the driver and front seat passenger
from hitting parts of the inside the vehicle while reducing the forces acting on the occupant during the crash. In this way they help to
reduce the risk of injury to the head and upper body in the crash.
Airbags do not protect the arms or the lower parts of the body .
Both front airbags wi ll not inflate in all frontal collisions. The trig­
gering of the airbag system depends on the vehic le dece leration
rate caused by the collision and registered by the electronic contro l
unit . If this rate is below the reference value programmed into the
control unit, the airbags will not be triggered, even though the car
may be badly damaged as a result of the collision . Vehicle damage, _,,
Vehicle care Do-it-yourself service Technical data

___ A_ ir_b _ a_ g=- s--=- y_s _t _e _m _________________________________________________ _
repair costs or even the lack of vehicle damage is not necessarily an
indication of whether an airbag should inflate or not.
It is not possib le to define a range of vehicle speeds that will cover
every possible kind and ang le of impact that wil l always trigger the
a irbags, since the circumstances wi ll vary cons iderably between
one co llision and another . Important factors include, for example,
the nature (hard or soft) of the object which the car hits, the angle of impact, vehicle speed , etc . The front airbags will also not inf late
in s ide or rear co llisio ns, or in rol l-overs .
Al way s remember : Airbags wi ll deploy only once , and on ly in certain
kinds of collisions. Yo ur safety belts are a lways there to offer protec ­
tion in those situat ions in which airbags are not supposed to deploy ,
or when they have already deployed; for example, when your vehic le
str ikes or is struck by another after the first co llision.
T his is just one of the reasons why an airbag is a supplem entary
r es tra int and is not a substitute for a safety be lt. The a irbag system
works most effective ly when used with the safety be lts . T herefore,
a lways properly wear your safety
be lts ~ page 176 .
& WARNING
Sitting too clo se to the steering wheel or instrument panel will
de cre ase the effect ivene ss of the airbags and will increase the risk
of personal injury in a colli sion.
• N ever si t closer than 10 in ches (25 cm) to the steer ing wheel or
in strument panel .
• If you cannot sit more than 10 inches (25 cm ) from the steering
wheel , inve stigate whether ad aptive equipment may be available
to held you re ach the pedal s and in crease your s eating distanc e
from the steering wheel.
• If you are unrestr ained , le aning forward , sitting sideways or out
of position in any way , your risk of injury i s much higher.
• You will also receive seriou s injuries and could even be killed if
you are up again st the airbag or too close to it when it infl ates
-
even with an Advanced A irbag .
& WARNING (continued )
• To reduce the risk of injury when an airbag inflates , always
we ar s afety belt s
properly ~ page 181, "Safety belt s".
• Alway s make certain that children age 12 or young er always
ride in the rear sea t. If children are not properl y re st ra ined , they
may b e severely injured or killed when an airbag inflate s.
• Never let children ride unre str ained or improperly restr ained in
the vehicle. Adjust the front seat s properly .
• Ne ver rid e w ith the b ackrest re clined.
• Alway s sit as far a s po ssible from the steering wheel or the
i nst rument
panel ~ page 168.
• Alway s sit upright with your ba ck ag ain st th e ba ckre st of your
s eat.
• Ne ver pla ce your feet on the in strument panel or on the seat.
Alwa ys keep both feet on the floor in front of the seat to help
prevent seriou s injuri es to th e le gs and hips if the airbag infl ates.
• Never re cline the front pa ssenger's seat to tran sport object s.
Item s can al so mo ve into the a re a of the side airbag or the front
airbag during braking or in a sudden m aneuver. Objects near the
airbags can becom e projectile s and cau se injury wh en an airbag
i nflates .
& WARNING
Airbags that have deplo yed in a cr ash must be replaced .
• Use only original equipment airb ag s a pproved by Audi and
in stalled by a trained techni cian who has the nece ssary tool s and
diagno stic equipment to pr operly repl ace any airbag in y our
vehicle and a ssure sys tem effectiv enes s in a crash .
• N ever p ermit salv aged or re cycled airb ags to be in sta lled in
y our vehicle. •

/b, WARNING (continued )
• Improper installation of child restraints can reduce their effec­
tiveness o r even prevent them from providing any protection .
• An improperly installed child restraint can interfere with the
airbag a s it deploys and ser iously injure or even kill the child -
even with an Advanced Airbag System .
• Alway s carefully follow the manufacturer's instructions
provided with the child safety seat or carrier .
• Never place additional items on the seat that can in crease the
total weight registered by the weight -sensing mat and can cause
injury in a crash. •
Front airbags
Description of front airbags
The air bag sys tem can pr ovi de s upp lem ental pro tecti on
t o p rop erly restr ained front se a t oc cupants.
Safety first
Fig . 177 Location of
driver airb ag : in
s teering wheel
( I p
Airbag system
Fig. 178 Location of
front pa ssen ger 's
airbag : in the instru­
ment p anel
Your vehic le is equipped with a dual -stage front "Advanced Airbag
System" in compl ia nce wi th Uni ted Sta tes Federa l Motor Ve hic le
Safety Standard (FMVSSl 208 as applicable at the time your vehicle
w as manufactured . Your vehicle is a lso equipped with side airbags
fo r the driver and front seat passenger . The safety belts for the front
seats have "pretensioners" that he lp to take s lack out of the belt
syste m. The p re te nsioners a re a lso activated by t he elec tronic
control unit for the airbag system.
The front safety belts a ls o have loa d lim iters to help reduce the
forces app lied to the body in a crash .
The airbag fo r the driver is in the steering wheel
hub => fig. 177 and
the airbag for t he front passenger is in the instrument pane l
=> fig. 178. The genera l location of the airbags is marked "AIRBAG" .
Th ere is a l ot you nee d t o know abou t the airbags in y our ve hicle. We
urge you to read the detailed information about airbags, safety be lts
and c hild safe ty in this and the ot her c hapt ers that mak e up the
owner 's lit erature. P lease be sure to heed the WARN INGS -they are
extremely importa nt for you r safety a nd the safety of you r passe n-
g ers, especially infants and small children.
..,
irechnical data

-Airbag system
----:=-..:....--------------------------------------------
& WARNING
Never rely on airbags alone for protection.
• Even when they deploy, airbags provide only supplemental
protection .
• Airbag work most effectively when used with properly worn
safety belts.
• Therefore, always wear your safety belts and make sure that
everybody in your vehicle is properly restrained.
& WARNING
A person on the front passenger seat, especially infants and small children, will receive serious injuries and can even be killed by
being too close to the airbag when it inflates.
• Although the Advanced Airbag System in your vehicle is
designed to turn off the front passenger airbag if an infant or a
small child is on the front passenger seat, nobody can absolutely
guarantee that deployment under these special conditions is
impossible in all conceivable situations that may happen during
the useful life of your vehicle.
• The Advanced Airbag System will deploy in accordance with
the
"low risk" option under the U.S. Federal Standard if a child that
is heavier than the typical one-year old child is on the front
passenger seat and the other conditions for airbag deployment
are met.
• Accident statistics have shown that children are generally safer
in the rear seat area than in the front seating position.
• For their own safety, all children, especially 12 years and
younger, should always ride in the back properly restrained for
their age and size.
•
Advanced front airbag system
Your vehicle is equipped with a front Advanced Airbag System in compliance with United States Federal Motor Vehicle Safety Stan­
dard 208 as applicable at the time your vehicle was manufactured .
The front Advanced Airbag System supplements the safety belts to
provide additional protection for the driver's and front passenger's
heads and upper bodies in frontal crashes. The airbags inflate only
in frontal impacts when the vehicle deceleration is high enough.
The front Advanced Airbag System for the front seat occupants is
not a substitute for your safety belts. Rather, it is part of the overall
occupant restraint system in your vehicle . Always remember that
the airbag system can only help to protect you, if you are sitting
upright, wearing your safety belt and wearing it properly. This is why
you and your passengers must always be properly restrained, not
just because the law requires you to be.
The Advanced Airbag System in your vehicle has been certified to
meet the "low risk" requirements for 3 and 6 year-old children on the
passenger side and very small adults on the driver side. The low risk
deployment criteria are intended to help reduce the risk of injury
through interaction with the front airbag that can occur, for example, by being too close to the steering wheel and instrument
panel when the airbag inflates .
In addition, the system has been certified to comply with the
"suppression" requirements of the Safety Standard, to turn off the
front airbag for infants 12 months old and younger who are
restrained on the front passenger seat in child restraints that are
listed in the
Standard~ page 272 .
"Suppression" requires the front airbag on the passenger side to be
turned off if:
• a child up to about one year of age is restrained on the front
passenger seat in one of the rear-facing or forward-facing infant
restraints listed in Federal Motor Vehicle Safety Standard 208 with
which the Advanced Airbag System in your vehicle was certified. For
~

___ A_ ir_b _ a_ g=- s--=- y_s _t _e _m _________________________________________________ _
&, WARNIN G (continu ed )
• The inflating airbag will hit the child s afety seat or infant
car rier with gre at for ce and will sma sh the child safe ty se at and
c hild agai nst the ba ckre st, center arm re st, door , or roof .
• Alwa ys in sta ll re arw ard -f aci ng child re str aint s in the b ack se at .
• If you mu st in stall a rearw ard facing child safety seat on the
front p assenger se at be cause of e xce pti ona l ci rc um stan ce s a nd
the PASSENGER AIR BAG OFF light doe s not come on and stay on ,
immedi atel y insta ll the re ar-f a cing child s afet y s ea t in a re ar
se ating position and h av e the airb ag sy stem inspe cted by your
Audi dealer .
& WARNING
If, in e xception al c ir cum sta nces, you mu st in sta ll a forward -f ac in g
c hild re straint on the front p assenger 's seat:
• Alway s mak e sure the forward-f acing seat ha s been designed
and certified by it s manufacturer for u se on a front seat with a
p asseng er front and side airb ag .
• Never put the forw ard -fa cing child re straint up again st or very
near the instrument panel.
• Alway s move the p assenger seat into it s re armost position in
the se at's fore and aft adju stment range , as far a way from the
a irbag a s pos sible , before installing the forward -f a cing child
rest raint . The ba ckrest must be ad justed to an upright po sitio n.
• Make sure that the PASSENGER AIR BAG OFF light come s on
a nd stay s on all th e time whenever the ignit ion i s swi tched on .
•
Advanced Airbag System components
The front passenger seat in your vehicle has a lot of very impo rtant
parts of the Advanced A irbag System in it . These parts include the
we ight -sensing mat , sensors, wiring, brackets , and more. The func -tion of the system in the front passenger seat is checked by the e
lec ­
tronic contro l unit w hen t he ignit ion is on . The co ntrol uni t monitors
the Advanced Airbag System and turns the airbag indicator light on
whe n a malfunction i n the system components is detected. T he
function of the airbag ind icator light is described in greater detai l
below. Because the front passenger seat contains important parts
o f the Advanced Airbag System, you must take care to prevent it
from being damaged . Damage to the seat may prevent the
Advanced Airbag for the front passenger seat from do ing its job in
a crash .
The front Adva nc ed Airbag S ystem consi sts of th e
following :
• Crash sensors in the front of the ve hicle that measure veh ic le
acce leration/deceleration to provide information to the Advanced
A irbag System about t he severity of t he crash .
• An electronic control unit, with integrated crash sensors for front
and side impacts. The control unit "dec ides" whethe r to fire the
front airbags based on the information received from the crash sensors . The control unit also "dec ides" whether the safety be lt
pretensioners should be activated.
• A dual -stage Advanced Airbag with gas generator for the driver
inside the steering wheel hub.
• A dual-stage Advanced A irbag and gas generator inside the
instrument pane l for the front passenger .
• A we ight -sensing mat under the upholstery padding of the front
passenger seat cushion that measures the tota l weight on the seat .
T he information registered is sent continuously to the electronic
control un it to regu late dep loyment of the front Advanced Airbag on
the passenger side .
• An airbag monitor ing system and indicator light in the instru ­
ment
cluster=> page 198 .
• The PASSENGER AIR BAG OFF light comes on and stays on in t he
center of the instrument panel
=> page 199, fig . 180 and te lls you
when the fron t Advanced Airbag on the passenger side has been
turned off.
~

Airbag system 111111
-----------------------------=--=-------
It is important to remember that while the supplemental airbag
system is designed to reduce the likelihood of serious injuries, other
injuries, for example swelling, bruising and minor abrasions, can
also happen when airbags inflate. Airbags do not protect the arms
or the lower parts of the body. Front airbags only supplement the
three point safety belts in some frontal collisions in which the
vehicle deceleration is high enough to deploy the airbags.
Front airbags
will not deploy:
• if the ignition is switched off when a crash occurs,
• in side collisions,
• in rear -end collisions,
• in rollovers ,
• when the crash deceleration measured by the airbag system is
less than the minimum threshold needed for airbag deployment as
registered by the electronic control unit.
The front passenger airbag
will also not deploy:
• when the front passenger seat is not occupied,
• when the weight on the front passenger seat as sensed by the
Advanced Airbag System indicates that the front airbag on the
passenger side has to be turned off by the electronic control unit
(the PASSENGER AIR BAG OFF light comes on and stays onl.
& WARNING
Sitting in the wrong position can increase the risk of serious injury
in crashes.
• To reduce the risk of injury when the airbags inflate, the driver
and passengers must always sit in an upright position, must not
lean against or place any part of their body too close to the area
where the airbags are located.
• Occupants who are unbelted, out of position or too close to the
airbag can be seriously injured by an airbag as it unfolds with
great force in the blink of an
eye :::::, page 189.
Controls and equip­ ment Safety first
Vehicle operation
& WARNING
A child in a rearward-facing child safety seat installed on the front
passenger seat will be seriously injured and can be killed if the
front airbag inflates
-even with an Advanced Airbag System.
• The inflating airbag will hit the child safety seat or infant
carrier with great force and will smash the child safety seat and
child against the backrest, center arm rest, door or roof.
• Always install rear-facing child safety seats on the rear seat.
• If you must install a rearward facing child safety seat on the
front passenger seat because of exceptional circumstances and
the PASSENGER AIR BAG OFF light does not come on and stay on, immediately install the rear-facing child safety seat in a rear
seating position and have the airbag system inspected by your
Audi dealer .
& WARNING
Objects between you and the airbag will increase the risk of injury
in a crash by interfering with the way the airbag unfolds or by
being 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 during
braking or other sudden maneuver and become dangerous projec ­
tiles 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, espe­
cially 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 _,,
Vehicle care Do-it-yourself service Technical data

& WARNING (continued)
• If you must install a rearward-facing child safety seat on the
front passenger seat because of exceptional circumstances and
the PASSENGER AIR BAG OFF light does not appear and stay on ,
immediately install the rear -facing child safety seat in a rear
seating posit ion and have the airbag system inspected by your
Audi dealer .
• A tight tether or other strap on a rearward-facing child restraint
attached to the front passenger seat can put too much pressure
on the weight-sensing mat in the seat and register more weight
than is actually on the seat. The heavier weight registered can make the system work as though an adult were on the seat and
deploy the Advanced Airbag when it must be suppressed causing
serious or even fatal injury to the child.
• 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 adjust­
ment range , as far away from the airbag as possible. The backrest
must be adjusted to an upright position . Make sure that the
PASSENGER AIR BAG OFF light comes on and stays on all the time
whenever the ignition is switched on .
& WARNING
• If the PASSENGER AIR BAG OFF light does not go out when an
adult is sitting on the front passenger seat after taking the steps
described above , make sure the adult is properly seated and
restrained at one of the rear seating positions .
• Have the airbag system inspected by your Audi dealer before
transporting anyone on the front passenger seat .
Controls and equip­ ment Safety first
Vehicle operation
Airbag system
[ i ] Tips
If the w eig ht-sens ing ma t in th e front passe nger seat detects an
e m pty seat , the front airbag on the pa ssenge r side wil l be turned
o ff , a nd PASSENGER AIR BAG OFF will stay o n.
a
Repair, care and disposal of the airbags
Pa rts o f the airba g sy ste m are i nsta lled at many d ifferen t pl aces on
y our Audi. Instal ling, removing , se rvicing or re pairing a pa rt in an
ar ea of th e ve hicle ca n da mage a part of an airbag syst em and
prevent that system from wor king properly in a co llision.
T he re a re so me impo rtant thin gs you have to know t o make sure
that the effectiv eness of the system will not be impaired and that
di scar ded co mpon ents do not ca use inju ry o r po llut e th e env iron­
m ent .
& WARNING
Improper care , servicing and repair pro cedures can increase the
risk of personal injury and death by preventing an airbag from
deploying when needed or deploying an airbag unexpectedly :
• Never cover, obstruct, or change the steering wheel horn pad
or airbag cover or the instrument panel or modify them in any way.
• Never attach any objects such as cup holders or telephone
mountings to the surfaces covering the airbag units .
• For cleaning the horn pad or instrument panel , use only a soft ,
dry cloth or one moistened with plain water . Solvents or cleaners
could damage the airbag cover or change the stiffness or strength
of the material so that the airbag cannot deploy and protect prop ­
erly .
• Never repair , adjust , or change any parts of the airbag system.
• All work on the steering wheel, instrument panel, front seats or
electrical system (including the installation of audio equipment ,
...,
Vehicle care Do-it-yourself service Technical data

_________________________________________ ___:l:.:.. n !.!t ~e :.:.11 :.!.ig ~e :.:..n !.!t :... t::.: e::.: c~ h:..:.:..,: n~o =.!l~o ~g Lly '.,_ _l!III
speed of the vehicle about its vertica l axis, the lateral acce leration
ac ting on the veh ic le, the brake pressure and the s teering ang le a re
a ll measured .
The direction in which the driver wishes to travel is determined with
the aid of the steering angle and veh icle speed and is continua lly
compared with the actual behavior of the vehicle. If the two do not
match, -for example, when the vehicle starts hydrop la ning on a
wet road -
, ESP will au tomatical ly brake the appropria te wheel to
correct the problem .
The vehicle is then stabi lized by the forces acting on the whee l
during braking . If the vehicle is
oversteering (r ea r tends to skid out
of the turn), t he brakes are main ly app lied on the whee l that is on
the outside of the curve . In the case of a vehicle that is
understeering
(tendency to s lide out of the curve) , the bra kes are applied at the
rear whee l that is on the inside of the curve. An acoustic signal indi ­
cates when ESP brake appl ication cuts in
=> & .
The system operates across the entire speed range in combination
wi th the ABS system
~ page 240. If the Ant i- Lock Brake Sys te m
(ABS) malfunctions, the ESP wi ll be out of act ion as well.
Ac tivat ion
When you turn on the engine, ESP will automatica lly be activated
and will perfo rm a self -test.
You can activate a deactivated ESP or deact ivated ASR as requ ired
by pressing the
=> page 236, fig. 199 button.
D eac tiva tion
Norma lly, the ESP should always be on .
When necessary, you can deact ivate Anti -Slip Regulat ion (ASR) or
the Electronic Stabilization Program (ESP) by pressing the button
=> page 236, fig. 199 .
• Dea ctivating A SR: Tap briefly on the ESP button . In certain excep ­
t iona l situations (e .g. driving wit h tire chains or a t a forced pace
around a track), the Anti-S lip Regu lation (ASR) can be deactivated
Controls and equip­
ment Safety first Vehicle operation
=> page
238 . The ESP check light flashes . T ap the ESP button again
t o r eact ivate ASR. The ESP check light g oes out .
• Deactiv ating ESP : Press the ESP button for more than 3 seconds .
W ith ESP deactivated, the ESP check ligh t illum inates cons tant ly .
Press the ESP button again to reactivate ESP . The ESP check light
g o es out .
& WARNING
The Electronic Stabilization Program i s neve rthele ss subject to the
laws of physi cs . It is part icularly important to pa y attent ion to thi s
fact on we t and slippery roads . It is therefore important that you
always adapt your driving to the condit ion of the road and traffic
c onditions. Do not allow the inc reased safety provided by the Elec ­
tronic Stabiliz ation Program sy stem to lull you into a ccepting
additional safety ri sk s.
• Plea se note that when ESP or ASR is dea ctivated , the drive
wheels can spin on icy and slippery roads and the vehicle can
break a way -da nger of skidding! •
Electronic differential lock (EDL)
The elec tr o nic differen tial l ock mon itors t he r ota tion al
speed of the drive wheels .
Gener al not es
The elec tronic d if f erential l ock (EDU helps the ca r to start mov ing,
accelerate and c limb a grad ient on surfaces providing poor or
a lmost n o grip. W ithout EDL, th is w ould be difficult, if no t impos ­
sib le.
How the system works
The EDL operates automatical ly. It monitors the rotational speed of
the drive whee ls on an ax le with the he lp of t he ABS senso rs
=> page 2 40 . If a noticeable difference in rotational speed between
the drive wheels on one axle is de tected (e .g. on sl ippery grou nd
on .,,.
Vehicle care Do-it-yourself service Technical data

-Intelligent technology
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one side), the spinning wheel is braked, thereby transferring power
to the other drive wheel or wheels (all- wheel drivel. This is done up
to a speed of about 60 mph (100 km/h). Noises from the brake
system signal that wheel spin is being control led.
Driving off
When driving off, always be sure to keep road conditions in mind as
you accelerate. If one drive wheel spins because it is on a surface
with less grip, gradual ly increase the pressure on the accelerator
pedal until the car starts to move. The wheel less able to transfer
power spins.
Overheating of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads, the EDL cuts out temporarily. The
veh ic le remains operational and behaves in the same way as a
vehic le without EDL.
As soon as the brake has cooled down, EDL switches on again auto ­
matically.
& WARNING
• When accelerating on slippery surfaces, such as on ice or snow,
always be careful when depressing the accelerator pedal. Even
with the EDL working, the drive wheels can spin and reduce your
ability to control your car . - Risk of crash!
• The increased safety afforded by EDL does not mean that you
ca n take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i ] Tips
If a fault occurs in the ABS, the EDL is also not functioning. This is
indicated by the ABS warning
light => page 21. •
Anti-Slip Regulation System (ASR)
The Anti-Slip Regulation System prevents the driven
wheels from spinning when the car is accelerating.
General notes
The Anti-Slip Regulation System (ASR) is integrated in the electronic
stabilization program (ESP) . When the vehicle starts up and acceler­
ates, the wheels are prevented from sp inning by adjus tin g the
engine power to match the amount of grip availab le from the road
surface.
How the system works
ASR performs automatical ly, i.e . w ithout the driver's intervention.
With the aid of the ABS
sensors=> page 240, ASR monitors the
speed of the driven wheels. If the wheels start to spin, the engine
power is reduced automatically until the tires find enough grip to
lock onto the road surface. The system is active across the entire
speed range.
The ASR works in conjunction with the ABS. If a malfunction shou ld
occur in the ABS, the ASR will also be out of act ion.
Activation
The ESP is automatica lly activated when the eng ine is started, and
it performs a self-test. You can activate a deactivated ASR, if
requ ired, by pressing
t h e=> page 236, fig . 199 button .
Deactivation
You can deactivate the ASR, if required, by pressing the button (for
less than 3
seconds) => page 236, fig. 199. With the ASR deactivated,
the ESP check light flashes,
see=> page 22.
Normally, the ESP shou ld always be on, however, it may be advanta­
geous to turn off the system in certai n special cases when some
degree of wheel spin is desired such as :
• when driving with snow chains