•
The direction in which the driver wishes to travel is determined with
t he aid of the steering angle and vehicle speed and is continua lly
compared with the actual behavior of the vehicle. If the two do not
match, for example, when the vehic le starts hydrop laning on a wet
road, ESP will automatically brake the appropriate whee l to correct
the prob lem.
The vehicle is then stab ilized by the forces acting on the whee l
during braking. If the vehicle is
oversteering (rear tends to skid out
of the turn), the brakes are mainly app lied on the wheel that is on
the outside of the curve. In the case of a vehicle that is
understeering
(tendency to sl ide out of the curve), the brakes are applied as
needed on the wheel that is on the inside of the curve or additionally
on the other wheels . An acoustic signal indicates when ESP brake
application cuts in
~ & .
The system operates across the entire speed range in combination
with the ABS system
~ page 292 . If the Anti-Lock Brake System
(ABS) malfunctions, the ESP will b e out of action as well.
Ac tiva tin g
When you turn on the engine, ESP will automatically be activated
and wil l perform a se lf-tes t. As soon as the test is comp leted, the
system is in norma l operating mode.
Offro ad m ode
ESP should normally be operated in normal mode because this
ensures maximum vehicle stabil ity . If necessary, you can activate
the ESP offroad mode by pressing the button
~ page 288, fig. 275
to obtain maxi mum traction and braking abil ity when dr iving off
paved roads at low speeds . In ESP offroad mode , the ESP indicator
l ight ~
page 19 illuminates and the message E S P Offroad appears
briefly in the display.
The ESP offroad mode can be usefu l in the fo llowing exceptional
s ituat ions when slip or a high ly effective differential locking func
tion is desirable. Examples:
• when driv ing with t ire chains,
• when driving in deep snow or on loose ground,
Inte llig ent tec hn olo gy
• when driving on uneven surfaces with the wheels severely
unloaded (articulation), and
• when rocking the vehicle loose after it has become stuck .
When the unusual situation is pas t, you should shift back to the
normal ESP operating mode by pushing the button again. The
message
ESP /A SR on then appears briefly in the display.
Hill d escent contr ol
The hil l descent control is swi tched on in ESP offroad mode . When
s lowly descending steep gradients on loose ground or when the
ax les are a rticulated, h ill descent control provides assistance by
automatically applying the brakes to keep vehicle speed constant.
The vehicle is also rendered easier to steer by se lective distribution
of braking force . Hi ll descent control intervenes when:
• the accelerator pedal is not pressed,
• the veh ic le is trave lling less than 12 mph (20 km/hl,
• a steep gradient is detected,
• whee l behavior indicates loose ground or conditions with poor
adhesion (e .g . also axle articulation).
Hi ll descent control operates both driving forward and in reverse.
Active hill descent contro l is deactivated by pressing the accelerator
pedal until the conditions for activat ion a lready listed are met again .
& WARNING
• The Elect roni c Sta bil izati on Progr am is ne ve rt hele ss subject to
th e law s of phy sics. It is particul arly important to pay attention to
t hi s fa ct on we t and slippery ro ads . It i s therefore i mpo rtant th at
yo u a lw ays adapt your dri vin g to the condition of the ro ad and
traffi c conditions . Do n ot allo w the in cre ased sa fety provided by
the Elect roni c Stabili zation Progr am system to lull you into
ac cepting additional safety r isks.
• Please be aw are th at in ESP offroad mo de, parti cularl y on a
s m ooth and slippery road , the wheel s m ay have an incr eased •
I t •
--~ln~ t ~e~ ll~ig ;t e~ n~t ...:t~ e::_: c::,: h '..!.'..: n~o ~ l.!::o
3g
:t; yL __________________________________________ _
& WARNING (continued)
tendency to spin and the vehicle may break away -danger of skid
ding!
• Stability is limited in the ESP offroad mode. •
Electronic differential lock (EDL)
The electronic differential lock monitors the rotational
speed of the drive wheels.
General notes
The electronic differential lock (EDU helps the car to start moving,
accelerate and climb a gradient on surfaces providing poor or
almost no grip . Without EDL, this would be difficult, if not impos
sible.
How the system works
The EDL operates automatically. It monitors the rotational speed of
wheels with the help of the ABS sensors=> page 292. If a noticeable
slip is detected at the wheels (e.g. on slippery ground on one side),
the spinning wheels are braked and power is transferred to the
other wheels. 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
controlled.
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, apply plenty of throttle until the car starts to move.
Overheating of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads on this wheel, the EDL cuts out tempo
rarily. The vehicle remains operational and behaves in the same way
as a vehicle 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
can 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 22. •
Anti-Slip Regulat ion 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 spinning by adjusting the
engine power to match the amount of grip available from the road
surface.
How the system works
ASR performs automatically, i.e. without the driver's intervention.
With the aid of the ABS sensors=> page 292, ASR monitors the
speed of the driven wheels. If the wheels start to spin, engine torque
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 should
occur in the ABS, the ASR wil l also be out of action.
& WARNING
The increased safety afforded by ASR does not mean that you can
take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i ] Tips
To ensure that the ASR works properly, all four wheels must be fitted
with identica l tires. Any differences in rolling radius of the tires can
cause the system to reduce engine power when this is not desired.
See also~
page 359, "New tires and rep lacing tires and wheels". •
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The brakes on today's automobiles are still subject to wear,
depending large ly on operating conditions and driving habits~& .
On vehicles that are either driven mostly in stop-and-go city traffic
or are driven hard, the brake pads shou ld be checked by your autho
rized Audi dealer more often than specified in the
Warranty & Main
tenance booklet.
Failure to have your brake pads inspected can
result in reduced brake performance.
On steep slopes, you shou ld use the braking effect of the engine .
This way, you prevent unnecessary wear on the brake system. If you
must use your brakes, do not hold the brakes down continuously.
Pump the brakes at intervals.
Controls and equip
ment Safety first Vehicle operation
Intelligent technology
Moisture
or road salt
If you are driving faster than 3 1 mph (50 km/h) and the windshield
wipers are on, the brake pads will briefly touch the brake discs in
regular intervals so as to improve reaction time when braking on
wet surfaces. You, the driver, will not notice anything.
Under certain conditions, for example, when driving through water
or very heavy rain, or even after washing your vehicle, the braking
effect can be reduced due to moisture (or in freezing conditions ice)
on the brake pads. A few careful brake applications sho uld dry off
the brake pads or remove any ice coatings .
The effectiveness of the brakes can be reduced when the vehicle is driven on a salt -covered road and the brakes are not used. Here too,
you should clean off accumulated salt coating from brake discs and
pads with a few carefu l app lications of the brake ~& .
Corrosion
There may be a tendency for dirt to build up on the brake pads and
corrosion to form on the discs if the car is not driven regularly or
only for short trips with litt le use of the brakes.
If the brakes are not used frequently, or if corrosion has formed on
t he discs, it is advisable to clean off the pads and discs by braking
firm ly a few times from a moderately high speed~&.
Faults in the brake system
If you shou ld notice a sudden increase in brake peda l trave l, then
one of the two brake circuits may have failed~& .
Low brake fluid le vel
Malfunctions can occur in the brake system if the brake fluid level is
too low . The brake fluid level is monitored electronically .
Brake lining wear status
Brake lining wear may be checked by visual inspection of the condi
tion of the brake pads through the openings in the wheel. If neces
sary, the wheel may be removed for this inspection
~ page 373,
"Changing a whee l" . ._.
Vehicle care Do-it-yourself service Technical data
___ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
& WARNING
• You should perform braking maneu vers for the purpose of
cleaning the brake system only if road conditions permit . Other
road u sers mu st not be put at r isk -you may cause an a ccident!
• Before des cending a steep grade, reduce speed and shift trans
mission into a lower gear or lower dr iving range . Do not ride the
brakes or hold the pedal down too long or too often. This could
cause the brake s to get hot and diminish braking effi ciency .
• Do not "ride the brakes " by resting your foot on the pedal when
you do not intend to b rake. This may cause the br ake s to ove rheat ,
premature wear and increased stopping distance.
• Under ce rtain climat ic and operating condit ions such as
passing through water , driving in heavy rain or after washing the
vehi cle , the effectiveness of the brakes can be reduced . In winter ,
ice can a ccumulate on the brake pads , linings , discs and drums .
Carefully apply bra kes fo r a test . Brakes will dry and ice coatings
will be cleaned off after a few careful brake appli cations .
• Driving for an extended period of time on salt -co vered roads
without using your brakes can also affect braking effic iency. Clean
off accumulated salt coating from brake dis cs and pads with a few
c areful brake applications .
• If you damage the front spoile r, or if you install a different
spoiler, be sure the air flow to the front brakes is not ob structed.
Otherw ise the brake sy stem could overheat reducing the effective
ness of the entire brake system .
• Failure of one bra ke cir cuit will impair the braking capability
resulting in an increased stopping distance. Avoid driving the
vehicle and ha ve it towed to the nearest authorized Audi dealer or
qualified workshop . •
Brake booster
T he b rake boost er ad ds extra b ra kin g powe r.
The brake booster works with vacuum pressure which is created
o nly w he n t he e ngine is ru nnin g=> & .
& WARNING
• Never let the vehicle roll to a stop with the engine shut off.
• If the brake booster is not working, for example when towing
your vehicle, or because the brake boo ster has somehow been
damaged , the brake pedal must be pressed considerably harder to
make up for the lack of booster assistance . •
Functioning of A!"lt"-Lock Brake System (ABS)
ABS p revents the wheels from locking up unde r brakin g.
Th e ABS co ntribu tes effect ively to vehicle cont ro l since it preve nts
the whee ls from
locking when the brakes are app lied. This means
t h at the ve hicle rema ins steerable and is less l ikely to s kid.
With ABS you do not need to pump the brake . Just hold the brake
pedal down .
However, do not expec t the A BS to s hor ten bra king d istance u nder
all circumstances. When driving o n grave l or on newly fallen snow
o n t op o f icy sur faces, brak ing d istance may be ev en lon ger, the re
fore, under these c ircumstances, it is especially important that you
driv e slow ly an d with gre at ca re.
How the ABS system works
An a utomatic c heck is m ade w hen a speed of about 1 2 mph (2 0
km/h) is reached. When this happens, a pumping noise can be
h ea rd.
If an individual wheel begins to rotate too slowly in relation to
vehicle speed and tends to lock, the ABS automatically reduces
brake pressure to prevent that wheel from locking.
This automatic adjustment process will cause a
slight vibration of
the brake pedal and some noises to alert you that vehicle speed
must be adapted to existing road and traffic conditions .
_& WARNING
Although the ABS is very effective, always remember that braking
capability is limited by tire traction. Always adjust your driving
speed according to the road and traffic conditions. Do not let the
extra safety afforded by the ABS tempt you into taking extra risks.
The ABS cannot overcome the laws of physics.
[ i] Tips
• If ABS is not functioning properly , a warning light will come on .
See
=> page 22.
• If a fault occurs in the ABS, the EDL is also not functioning. This
is indicated by the ABS warning light.•
Brake assistant
The brake assistant is designed to achieve the optimum
braking effect.
The brake assistant helps to increase the effective braking power
and thus to achieve
a shorter stopping distance . If the driver
presses the brake pedal very quickly , the brake assistant automati
cally boosts the braking force to the maximum level, up to the point
where the anti-lock brake function (ABS) intervenes to stop the
wheels from locking. You should then keep th e brake pedal pressed
until the vehicle has braked to the required speed. The brake assis
tant swi tches its elf off as soon as you release the brake pedal.
Controls and equip
ment Safety first Vehicle operation
Intelligent technology
Automatic full braking assist
This function allows full braking
in spite of high brake pedal forces
(e.g . when the brakes are severely stressed because the vehicle is
fully loaded) . The driver notices this function through a reduction of
pedal force and increased pedal travel. When the brake pedal is
released, full braking assist switches off again automatically.
If there is an ABS failure, the brake assistant and automatic full
braking assist ar e not available .
The brake assistant will not be operative if there is a malfunction in
the ABS.
_& WARNING
Please remember that the accident risk always increases if you
drive too fast, especially in corners or on a slippery road, or if you
follow the vehicle ahead of you too closely . Increased risk of an
accident cannot be compensated for even by the brake assistant,
so always maintain a safe speed. iJ
Servotronic® -advanced power
steering system
The power steering systems uses the power of the
running engine to allow precise steering with little effort.
The advanced Servotronic ® power steering system senses the road
speed and electronically adjusts power assistance to provide
comfortable and safe steering response exactly matched to the
vehicle speed.
Power steering will not work if the engine is off. As a result, the
s teering whe el will be hard to turn.
The power steering fluid level is checked during the scheduled
maintenance services .
•
Vehicle care Do-it-yourself service Technical data
lffll __ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
0 Note
If there is an electronic malfunction, servotronic will still function
like a conventional power steering system, providing a constant
steering support force that is no longer proportionate to the vehicle
speed. This is most noticeable when turning the steering wheel at
low speeds ( for example when parking), - more effort will be
required than usual.
• Be aware of the different than usual steering response and
adjust your steering force accordingly.
• Have the problem checked and set right by an Audi dealer as
soon as possible.
[ i] Tips
• When the engine is running, never hold the steering wheel
turned all the way to the right or to the left for longer than 15
seconds . Th e power steering pump will overheat the hydraulic fluid
if you keep holding the steering wheel turned all the way. This is
likely to damage the power steering system .
• If the power steering system should fail entirely, or if the engine
is not running (for example, while being towed), you will still be able
to steer the vehicle. However,
considerably more effort will be
required to do so.
• If the power steering system should have a leak, or is not func
tioning properly, contact your authorized Audi dealer immediately.
• The power steering system requires a specially formulated
hydraulic fluid. The power steering reservoir is the one located
farthest to the rear on the left side of the engine compartment
=>
page 332. The correct fluid level in the reservoir is important for
proper functioning of the power steering. •
Driving with your quattro®
---------
With All Wheel Drive, all four wheels are driven.
General information
With All Wheel Drive, power is distributed to all four wheels. This
happens automatically depending on your driving style and the
road conditions at the time. See also=>
page 290, "Electronic differ
ential lock (EDU" .
Winter tires
When driving in the winter, your vehicle with All Wheel Drive has an
advantage, even with regular tires. In winter road conditions it may
be advisable to mount winter tires (or all-season tires) for improved
driveability and braking: these tires must be mounted on
all four
wheels .
See also=> page 363, "Win ter tires".
Tire chains
Where tire chains are mandatory on certain roads, this normally
also applies to vehicles with All Wheel Drive=>
page 364, "Snow
chains".
Replacing wheels/tires
Vehicles with All Wheel Drive must always have tires of the same size. Also avoid tires with different tread depths. For details see
page=:>
page 359, "New tires and replacing tires and wheels".
& WARNING
Always adjust your driving to road and traffic conditions. Do not let the extra safety afforded by All Wheel Drive tempt you into
taking extra risks .
• Although the All Wheel Drive is very effective, always
remember that braking capacity is limited by tire traction. You
should therefore not drive at excessive speeds on icy or slippery
road surfaces .
~
& WARNING (continued)
• On wet road surfaces, be careful not to drive too fast because
the front wheels could begin to slide on top of the water (aqua
planing) . If this should occur , you will have no warning from a
sudden increase in engine speed as with a front -wheel drive
vehicle. Always drive at speeds which are suited to the road condi
tions -risk of crash. •
Energy management
Starting ability is optimized
Energy management controls the distribution of electrical
energy and thus optimizes the availability of electrical
energy for starting the engine.
If a vehicle with a conventional energy system is not driven for a
long period of time, the battery is discharged by idling current
consumers (e.g. immobilizer). In certain circumstances it can result
in there being insufficient energy available to start the engine.
Intelligent energy management in your vehicle handles the distribu
tion of electrical energy. Starting ability is markedly improved and
the life of the battery is extended.
Basically , energy management consists of
battery diagnosis, idling
current management
and dynamic energy management .
Battery diagnosis
Battery diagnosis continuously determines the state of the battery.
Sensors determine battery voltage, battery current and battery
temperature. This determines the current state of charge and the
power of the battery.
Controls and equip ment Safety first Vehicle operation
Intelligent technology
Idling current management
Idling
current management reduces energy consumption while the
vehicle is standing. With the ignition switched off, it controls the
energy supply to the various electrical components. Data from
battery diagnosis is considered.
Depending on the battery's state of charge, individual consumers
are gradually turned off to prevent excessive discharge of the
battery and thus maintain starting capability.
Dynamic energy management
While the vehicle is being driven, dynamic energy management
distributes the energy generated according to the needs of the indi
vidual components. It regulates consumption, so that more elec
trical energy is not being used than is being generated and ensures
an optimal state of charge for the battery.
[ i] Tips
• But even energy management cannot negate the limits of
physics. Consider that the power and life of a battery are limited.
• I f starting ability is threatened, you are informed by a warning
~ page 296, "Driver notification in the instrument cluster
display". •
What you should know
-----------------
The highest priority is given to maintaining starting capa-
bility.
Th e battery is severely taxed in short -distance driving, in city traffic
and during the cold time of year. Abundant electrical energy is
required, but only a litt le is generated. It is also critical if the engine
is not running and electrical components are turned on. In this
instance energy is being consumed but none is being generated.
It is in precisely these situations that you will notice energy manage
ment actively regulating the distribution of energy.
•
Vehicle care Do-it-yourself service Technical data
llffl __ ln_ t _e_ ll-'"ig ...,_ e_ n_t _t_ e_ c_ h _ n_o _ l_o _,.g= y,_ __________________________________________ _
Vehicle stands for an extended period
If you do not drive your vehicle over a period of several days or
weeks, electrical components are gradually cut back or switched off.
This reduces energy consumption and maintains starting capability
over a longer period.
Take into consideration that when you unlock your vehicle, some
convenience functions, such as the remote key or power seat
adjustment, may not be available. The convenience functions will be
available again when you turn on the ignition and start the engine.
With the engine turned off
If you listen to the radio, for example, with the engine turned off or
use other MMI functions, the battery is being discharged.
If starting capability is jeopardized due to energy consumption, the
following warning appears in the MMI display:
Please start engine, otherwise system will switch off in
3 minutes.
The warning indicates that the system will be turned off automati
cally after 3 minutes. If you wish to continue using the functions,
you have to start the engine.
With the engine running
Although electrical energy is generated when the vehicle is being
driven, the battery can become discharged. This happens mostly
when little energy is being generated and a great deal consumed and the battery's state of charge is not optimal.
To bring the energy balance back into equilibrium, consumers
which require especially large amounts of energy are temporarily
cut back or switched off. Heating systems in particular require a
great deal of energy. If you notice, for example, that the heated
seats* or the heated rear window are not heating, they have been
temporarily cut back or switched off. These systems will be available
again as soon as the energy balance has been restored.
You will also notice that engine idle speed has been increased
slightly. This is normal and not a cause for concern. By increasing engine idle speed the additional energy required is generated and
the battery is charged. •
Driver notification in the instrument cluster
display
If battery power drops into the range where it can limit the ability of
the engine to start, this is shown in the instrument cluster display
with the following driver message:
C Low battery charge: battery will be charged while driving
This notification reminds you that the starting capability of the
engine may be limited. As soon as you start driving again, the
battery will be recharged and the notification will go out.
Driver notification appears and goes out again
If this driver notification appears after the ignition is turned on or
while driving and it goes out again after a while, the battery has
been adequately recharged.
Driver notification appears and does not go out again
If this driver notification appears after the ignition is turned on or
while driving and does not go out again, the battery's state of
charge is not in the optimal range. Starting ability is restricted. Have
the battery checked as soon as possible by an authorized Audi dealer or qualified workshop. •