2008 AUDI S6 check engine

When the abnormal situation is over, you should activate the ASR
again.
& 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 identical 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 325, "New tires and replacing 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 largely on operating conditions and driving habits~& .
On vehicles which are driven mostly in stop-and-go city traffic or
which are driven hard, the brake pads should be checked by your
authorized Audi dealer more often than specified in the
Mainte­
nance
& Warranty booklet.
On steep slopes, you should 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 50 mph (80 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 should 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 careful applications 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 little use of the brakes.
If the brakes are not used frequently, or if corrosion has formed on
the discs, it is advisable to clean off the pads and discs by braking
firmly a few times from a moderately high speed~&.
Faults in the brake system
If you should notice a sudden increase in brake pedal travel, then
one of the two brake circuits may have failed~& .
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is
too low . The brake fluid level is monitored electronically .
& WARNING
• You should perform braking maneuvers for the purpose of
cleaning the brake system only if road conditions permit. Other
road users must not be put at risk -you may cause an accident!
Vehicle care Do-it-yourself service Technical data

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& WARN ING (continued )
• Before des cending a steep grade , reduce speed and shift trans­
mission into a lower gear or lower dr iving range. D o not r ide the
brakes or hold the pedal down too long or too often . This could
c au se the brake s to get hot and dimin ish 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 brakes to overheat ,
premature wear and in crea sed stopping distan ce.
• Under certain climat ic and oper ating condit ion s s uch as
passing through water, driving in heavy rain or after washing the
vehicle , the effectiveness of the brakes can be reduced. In winter ,
ice c an a ccumulate on the brake pads , linings , discs and drums .
Carefully apply brakes fo r a test. Brakes will dry and ice coatings
will be cleaned off after a few careful brake applications .
• Driving for an e xtended pe riod of time on salt-covered road s
without using your brakes can also affect braking efficiency . Clean
off accumulated salt coating from brake disc s and pads with a few
careful 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 obstructed .
Otherwise the brake system could overheat reducing the effective ­
ness of the entire br ake system .
• Failure of one brake circuit will impair the braking capability
resulting in an increased stopping distance . Avo id driving the
vehicle and have it towed to the nearest Audi dealer or qualified
workshop .
u
Brake booster
T he brake boo ster ad ds e xtra bra kin g pow er.
T he brake booster works with vacuum pressure which is created
only when t he en gine is run ning~ &.
& WARNING
• Never let the vehi cle roll to a stop with the engine shut off .
• If the brake boo ster is not working, for example when towing
your vehicle , or because the brake booster has somehow been
damaged, the brake pedal must be pre ssed considerably harder to
make up for the lack of booster assistance . •
Functioning of Anti-Lock Brake System (ABS)
-- --
ABS preven ts the wheels from l ocking up und er bra kin g.
T he ABS contributes effectively to vehicle contro l since it prevents
th e w hee ls fr om lo cking when the brakes a re app lied . T hi s m ea ns
that the vehicle remains steerable and is less l ikely to skid.
With ABS you do not need to pump the brake . Just hold the brake
pedal down .
H owever, do not expect the AB S to shorten braking distance under
all circu ms tances. When drivi ng on grave l or on newly fa lle n sn ow
on top of icy surfaces, braking distance may be even longer, there ­
f o re, unde r these c ircums ta nces , it is es pecially imp ortant th at you
drive slow ly and with great care .
How the ABS system works
An automatic check is made when a speed of about 4 mph (6 km/h)
i s r eac hed . W he n th is happens, a pumping n oise ca n be heard.
I f a n indiv idual wheel be gins to rotat e too slowly in relation to
vehic le speed and tends to lock, the ABS automatically reduces
brake pressur e to p revent that whee l from loc king .
T his automatic adjustment p rocess will cause a slight vibration of
t he brake peda l a nd some noi ses t o a le rt yo u th at ve hicle speed
must be adapted to ex isting 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 the brake pedal pressed
until the vehicle has braked to the required speed. The brake assis ­
tant switches itself off as soon as you release the brake pedal.
The brake assistant will not be operative if there is a malfunction in
the ABS.
In vehicles with Adaptive Cruise Control* (ACC), the distance to the
vehicle ahead is continuously calculated using a radar sensor,
within the limits of the system=>
page 135. If the radar system
detects a short distance to the vehicle ahead, the brake system
exerts a small braking force to reduce the brake response time in
Controls and equip­
ment Safety first Vehicle operation
Intelligent technology
case of braking. In this way, the brake application can be quickened
and
the stopping distance reduced.
& 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.
n
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
steering wheel will be hard to turn.
The power steering fluid level is checked during the scheduled
maintenance services.
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.
II-
Vehicle care Do-it-yourself service Technical data

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• Be aware of the different than usual steering response and
adj ust you r steer ing for ce accordingly.
• Have the problem checked and set right by an Audi dealer as
s o on as possible .
[ i ] Tip s
• When th e engine is running, never hold the steering whee l
turned all the way to the right or to the left for longer than 15 seconds. The power steering pump will overheat the hydrau lic
fluid if you keep ho lding the steering wheel turned all the way. This
is like ly 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 wil l 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 ­
tioni ng 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 most
forward on the left side of the engine compartment~
page 298. The
correct fluid level in the reservoir is important for proper func ­
tioning of the power steering.
App lies to vehic les: with A ll Wheel Dr ive
Dr iving with your quattro®
With All Wheel Drive, all four wheels are driven.
Gen era l i nfo rm ati on
With All Wheel Drive, power is d istr ibuted to all four whee ls. Th is
happens automatica lly depending on your driving style and the
road conditions at the time. See also ~
page 259, "Electronic differ ­
entia l lock (EDU".
Wint er tir es
When driving in the winte r, 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
a ll fou r
wh eel s.
See also ~ page 329, "Winter tires".
Tire chains
Where tire chains are mandatory on certain roads, this normally
a lso app lies to veh icles with A ll Wheel Drive~
page 330, "Snow
chains".
R epl acing w hee ls/t ires
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 325, "New tires and replacing tires and wheels" .
Off-R oa d dri ving?
Your Audi does no t have enough ground c learance to be used as an
off -road vehic le. It is therefore best to avoid rough tracks and
uneven terrain as much as possible . Also refer to~
page 269.
& WARNING
Always a djust yo ur driving to r oad and traffi c condition s. Do not
let the e xtr a s afet y affor ded b y All Whee l Dri ve tempt you into
taking extr a risks.
• Although the All Wheel Dr ive i s very effe ct ive , a lwa ys
r e member that braking capacity i s limited b y tire trac tion. You
s hould therefore not d riv e at e xcess iv e speed s on icy or slipp ery
road surfaces .
• On we t road surf aces, be care fu l no t to d riv e t oo fas t beca use
the front whe els could b egin to slid e on top of the w ater (aqu a­
planing ). If t his sho uld occ ur, you will h ave no warn ing from a
s udden incr ease in engine sp eed a s with a front -wh eel drive
v ehicl e. Alwa ys dri ve at spee d s w hic h are s uited to th e road condi ­
tion s - risk of cra sh.
;:i

-Intelligent technology
----'""------- ~---------------------------------------
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
d isplay
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:
'-' 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 at a dealership. •

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•
from fading. Slight color variations will develop in normal use and
are not an indication of material deterioration.
0 Note
• Never use chemical solvents (e.g. lighter fluid, turpentine),
waxes, shoe polish or similar products on Alcantara ® surfaces.
• To avoid damage, have stubborn stains removed by a commer­
cial cleaning specialist.
• Do not use brushes, stiff sponges or similarly abrasive cleaning
aids .•
Safety belts
Only well-maintained safety belts work reliably when
needed.
- Keep belts clean.
- For cleaning, use a mild soap and water solution . Let
belts dry thoroughly and away from direct sunlight .
- Do not allow inertia reel safety belts to retract before
they are completely dry.
- Check the condition of your safety belts
regularly.
Heavily soiled safety belts may not retract properly.
& WARNING
Damaged safety belts can break in a crash.
• Anything that might damage your safety belts could mean that
you and your passengers would not be adequately protected in an
accident.
• Safety belt performance depends on correct installation. Never
remove belts from the vehicle to clean them.
& WARNING (continued)
• Do not use chemical cleaning agents, bleach or dyes. They have
corrosive properties which weaken the webbing.
• When cleaning your safety belts, inspect them for damage. If
you discover damage, see your Audi dealer.
• Always read and heed all WARNINGS and other information
~ page278. a
Engine compartment
Be especially careful when cleaning the engine compart­
ment.
Always switch off the ignition before cleaning the engine ~ &.
Plenum panel
Remove leaves from the plenum panel in front of the windshield
under the engine hood. This prevents the water drain holes from
becoming blocked, and it prevents debris from entering the vehicle
interior through the heating and ventilation ducts.
Corrosion protection
The engine compartment and transmission have been corrosion­
protected at the factory.
Good anti -corrosion treatment is very important, particularly in the
winter. If the vehicle is frequently driven on salt treated roads, the
entire engine compartment and plenum panel should be thor­
oughly cleaned at the end of winter and retreated to prevent salt
damage. At the same time, the underside of the vehicle should be
washed as well.
If the engine compartment is cleaned at any time with grease
removing solutions
1 l, or if you have the engine washed, the anti­
corrosion treatment is almost always removed as well. It is therefore .,_
11 Use only th e correct cleaning solut ions. N ev er use gasolin e or di ese l fu el.
Vehicle care I t •

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Checking and filling
Engine hood
Releasing the engine hood
The engine hood is released from inside the vehicle.
-Open the driver's door .
Fig. 229 Driver's side
footwell: engine hood
release lever
-Pull the release lever on the left under the instrument
panel
=> fig. 229 in the direct ion of the arrow.
The hood pops up slightly under spring pressure. •
Opening the engine hood
Fig. 230 Release lever
under the engine hood
Before opening the engine hood, make sure that the wind­
shield wipers are flat against the windshield. Otherwise,
they could damage the paint on the hood.
Lift the hood slightly =>&, .
Pull up on the release under the hood => fig. 230. This
releases the catch.
- Open the hood all the way.
The hood is kept in the open position by two gas struts.
& WARNING
Hot engine coolant can burn you.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood. •

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•
Closing the engine hood
- Pull the hood down until the pressure from the struts is
reduced .
- Let the hood
drop down and latch in place. Do not try to
push it shut;
it may fail to engage => &.
& WARNING
A hood that is not completely latched could fly up and block your
view while driving.
• When you close the engine hood, check it to make sure the
safety catch has properly engaged. The hood should be flush with
the surrounding vehicle body parts.
• If you notice while driving that the hood is not secured prop­
erly, stop at once and close it. •
Working in the engine compartment
Be especially careful whenever you work in the engine
compartment.
Whenever you must perform any work in the engine compartment,
for example checking and filling different fluids, there is a risk of injury, burns and accidents. To prevent personal injury always
observe the following WARNINGS. The engine compartment of any
vehicle is a hazardous area
~ & .
& WARNING
To help avoid injury, before you check anything under the hood :
• Turn off the engine.
• Remove the ignition key.
• Apply the parking brake .
& WARNING (continued)
• Move selector lever to "P" (Park).
• Always let the engine cool down. Hot components will burn
skin on contact.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood.
• Keep children away from the engine compartment .
• Never spill fluids on hot engine components. They can cause a
fire.
• Never touch the radiator fan. The auxiliary electric fan is
temperature controlled and can switch on suddenly.
• Never open the coolant reservoir cap when the engine is still
warm . The coolant system is pressurized and hot coolant could
spray out.
• Protect your face, hands and arm from steam or hot engine
coolant by placing a thick rag over the cap when you open the
coolant reservoir.
• If work on the fuel system or the electrical system is necessary :
- Always disconnect the battery.
- Never smoke or work near heaters or open flames . Fluids in
the engine compartment could start a fire.
- Keep an approved fire extinguisher immediately available.
• To avoid electrical shock and personal injury while the engine
is running or being started, never touch:
- Ignition cables
- Other components of the high voltage electronic ignition system.
• If you must perform a check or repair with the engine running: -First, fully apply the parking brake, move selector lever to "P"
(Park). .,
Vehicle care
I t •