check engine light AUDI A4 AVANT 2008 Owner's Manual

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& 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 21.
• 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.
Controls and equip­
ment Safety first
Vehicle operation
& 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. An increased accident
risk cannot be compensated even by the brake assistant, so
always maintain a safe speed. •
Servotronic® -advanced power
steering system
The power steering systems uses the power of the
running engine to allow precise steering with little effort. Your Audi is equipped with the electronically controlled
Servotronic® advanced power steering system. It adjusts
the degree of steering assistance to the roadspeed.
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.
.,.
Vehicle care Do-it-yourself service Technical data

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_ r_o _ n_ m_ e_ n_ t _______________________________________________ _
one half. Never drive faster than the posted speed limit and weather
conditions permit. •
Reducing unnecessary idling
Even when your car is just idling it burns up fuel.
- Shut the engine off when you are not driving the vehicle .
- Do not warm up the vehic le by letting the engine run at
id le .
It makes sense to shut off the engine in traff ic jams, when waiting
for tra ins to pass at rai lroad crossings , or at traffic lights that have
long waits on red. Turning the engine off for just 30 -40 seconds
saves more fue l than is burned starting the engine again .
It takes a long time for the engine to warm up fu lly when it is
running at idle. However, wear and noxious emiss ions are espec ially
high when the engine is warming up . So you should drive away as
soon as you sta rt the engine and avoid running at high rpms w hile
the engine is sti ll warming up.
0 Note
Do not leave engine idling unattended after starting . If warning
lights should come on to indicate improper operation, they would
go unheeded. Extended id ling also produces heat, which could
resu lt in overheating or other damage to the vehic le or other
property .•
Regular maintenance
A badly tuned engine unnecessarily wastes a lot of fuel.
- Have your ve hicle serviced at regular intervals .
By having your vehicle regularly serviced by an Audi dealer helps to
ensure that it runs properly and economical ly . The cond ition of your
vehic le not only affects its safety and abi lity to hold its value, it also
affects
fuel consumpt ion .
Check your oil ea ch time you fill your t ank .
The amount of oil used is related to engine load and speed.
I t is norma l for the oi l consumption of a new engine to reach its
lowest value after a certain mi leage has been driven.
You must drive your vehicle about 3,000 miles (5,000 kilometers) before you can properly assess oil consumption .
This also applies to fue l consump tion and engine output .
0 Note
• Have your vehicle maintained properly and in accordance with
t he service recom mendat io n s in your Maintenance
& Wa rranty
booklet. Lack of proper ma intenance as well as improper use of the
vehic le wi ll impai r the function of the emission cont rol system and
cou ld lead to damage.
• Do no t alte r or remove any component of the Emission Contro l
System unless approved by the manufacturer .
• Do not alte r or remove any dev ice, such as heat shields,
switches, ignition wires, valves, which are designed to protec t your
vehic le's Emission Control System and other important veh ic le
components .•
Fewer short trips
Fuel consumption will alw ays be rel atively high on short
t r ips.
- Try to avo id driving short dis ta n ces wi th a cold engine. ~

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Trailer towing
Driving with a trailer
General information
Your Audi was designed primarily for passenger transpor­
tation.
If you plan to tow a trailer, please remember t hat the add it ional load
wi ll affect durability, economy and performance.
Trailer towing not only p laces more stress on the veh icle, it a lso ca lls
for more concentration from the driver.
For th is reasons, always fo llow the operating and dr iving instruc ­
t ions provided and use common sense. •
Technical requirements
Trailer hit ch
Use a weight -carrying hitch conforming to the gross trailer weight.
The hitc h must be suitab le for your veh ic le and tra iler and must be
mounted securely on the vehicle's chassis at a technically sound
l ocation. Use only a tra iler hitch with removable bal l mount. A lways
check with the trai ler hitch manufacturer to make sure that you are
using t he correct hitch .
Do not use a bumper hit ch .
The hitch must be installed in such a way that it does not interfere
with the impact-absorb ing bumper system . No mod ifications
shou ld be made to the vehicle exhaust and brake systems. From
time to time, check that all hitch mount ing bo lts re main securely
fastened.
When you are not towing a trai ler, remove the trailer hit c h ball
mount. Th is prevents the hitch from causing damage s hou ld your
vehic le be struck from
behind ~& .
Tire pre ssure
When towing a trailer, inf late the tires of your vehic le to the cold tire
pressure listed under "Full load" on the s ticker on the right door­
jamb . Inflate trai ler tires to tra iler and tire manufacturers' specifica­
t ions.
Lights
T he head ligh t settings shou ld be checked with the trailer at tached
before driving off. Have the head lights adjusted as necessary so
t hat you can see t he road ahead bu t not bl ind oncom ing traffic.
Check to make sure both vehicle and trailer lights are working prop ­
e rly .
Engine cool ing sy stem
Towing a t railer makes the eng ine work ha rder. It is imp ortant tha t
the cooling system's performance stands up to the additiona l
strain. Make sure that the coo ling system has enoug h fluid.
Traile r br ake s
If your tra ile r i s eq uipped wi th a braki ng system, check to be s ure
that it conforms to al l regu lations .
T he tra iler hydraulic brake system must no t be direct ly connected to
the vehic le's hydrau lic brake system .
Safety chains
Be sure trailer safety chains are properly connected from the trai ler
t o the h itch on the vehicle. Leave enough s lack in t he chains to
permit turning corners. When you install safety chains, make sure
they will not drag on the road when you are driving.
T he chains shou ld cross under t he trailer tongue to prevent it from
dropping in case of separation from the hitch. _,,,

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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.
• 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 the information
=> page 254. •
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
21 , or if you have the engine washed , the anti­
corrosion treatment is almost always removed as well. It is therefore
essential to have a long-lasting corrosion protection reapplied to all
surfaces, seams, joints and components in the engine compart ­
ment.
& WARNING
Be aware: the engine compartment of any motor vehicle is a
potentially hazardous area.
• Before working in the engine compartment, be sure to read the
information
=> page 265 . .,,_
21 Use only the corr ect cleaning solutions. Never use gasoline or diesel fuel.
Vehicle care

-Checking and filling Pll':f..._--=--=--------------
Checking and filling
Engine hood
Releasing the engine hood
The engine hood is released from inside the vehicle.
Fig. 203 Driver's side
footwell: engine hood
release lever
- Pull the release lever on the left under the instrument
panel=> fig. 203 in the direction of the arrow.
The hood pops up slightly under spring pressure. •
Opening the engine hood
Fig. 204 Release lever
under the 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 the release under the hood => fig. 204. This releases
the catch.
- Open the hood all the way.
The hood is kept in the open position by a gas strut.
& 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-.,..

Checking and filling -
------------ ----=---a::;;._...a
©
©
(i)
Coolant expansion tank ( ... L) ...... ... .. ..... .. ... .
Windshield/headlight washer container
( 0 ) ...... . .
Power steering reservoir (green cap)
& WARNING
Before you check anything in the engine compartment, always
read and heed all WARNINGS
=> & in "Working in the engine
compartment" on
page 273. •
Applies to vehicles: with 6 -cy lin d er engine
3.2 liter , 6-cylinder engine (255 hp)
281
291
241
These are the most important items that you can check.
Fig . 206 Engine compartment: 3 .2 liter , 6-cylinder
CD
0
©
Battery .. ............... ... .. ...... .... ...... .
Brake fluid reservoir (
... ) . .. ... ... .... .... ...... .
Coo lant expansion tank
(J _)
285
284
281
©
©
©
(i)
Engine oil filler cap ( Engine oil dipstick (orange) .. .... ..... ... .... ... .
Windshield/headlight washer container
( O ) ... .... .
Power steering reservoir (green cap)
& WARNING
Before you check anything in the engine compartment , always
read and heed all WARNINGS
=> & in "Working in the engine
compartment" on
page 273. •
Engine oil
Engine oil specifications
278
277
291
241
The engine oil used in your Audi needs the right kind of
oil.
The engine in your Audi is a sophisticated powerplant that was built
to exacting specifications . This engine needs the right kind of
engine oil that meets specifications regarding quality and viscosity
so that it can run smoothly and re liably . Choosing the right oil and
changing oil within the time and mileage intervals printed in your
vehicle's Maintenance
& Warranty booklet matters a lot more today
than it did years ago. Audi has developed a special quality standard
f or engine oil that wil l help assure that your vehicle's engine wi ll get
the lubrication it needs for proper operation .
Modern engine lubrication has taken a quantum leap in the last few
years. Many synthetic oils available today provide better engine
lubrication that can outlast traditional petroleum-based oils,
making them a smart choice for use throughout the life of your Audi .
Whether you use synthetic or petroleum -based engine oil, the oil
that you use must conform to Audi's oi l quality standard VW 502 00
to help keep your vehicle 's engine running smoothly and help
.,_
Ve hic le care Technical data

Checkin g a nd fillin g --------------~~~-
the form of Service or Repair Orders that all scheduled maintenance
was performed in a t ime ly manner .•
Engine oil consumption
The engine in your vehicle depends on an adequate
amount of oil to lubricate and cool all of its moving parts.
In order to prov ide effect ive lubrication and cool ing of in ternal
engine components, all internal combustion engines consume a
certain amount of o il. Oil consumption varies from engine to engine
and may change significantly over the life of the engine . Typically,
eng ines wi th a specified break -in period
(see ~ page 243) consume
more oil during the break -in period than they consume after oi l
consumption has stabi lized .
Under norma l condit ions, the rate of o il consumption depends on
the quality and viscosity of the oil, the RPM (revo lutions per minute)
at whic h the engine is operated, t he amb ient te mperature and road
conditions. Further factors are the amount of oil dilution from water
condensatio n or fuel residue and t he oxidation level of the o il. As
any engine is subject to wear as mileage builds up, the oil consump ­
t ion may increase over time until rep laceme nt of worn components
may become necessary .
With all these variables coming into play, no standard rate of oil consu mption can be estab lished or specified. T here is no a lternative
to regu lar and frequent checking of the oil level, see
Note .
If the yellow eng ine o il level warni ng symbol in the instrument
cluster ~ lights up, you should check the oil level as soon as
possible
with the oil dipstick ~ page 277 . Top off the o il at your
earl iest
convenience~ page 278.
& WARNING
Bef ore you che ck anything in the eng ine comp artment , alway s
read and heed all WARNINGS
~ & in "Working in the engine
c ompartment " on
page 27 3.
0 Note
Driving with an insuff ic ient oil level is l ikely to cause severe damage
to the engine.
[ i ] Tip s
• The oil pres sure warning displ ay "e:7: is n ot an indi cator of the oil
level . Do not rel y on it. Instead, check the oil level in your engine at
regular inter vals, preferably ea ch time you refuel , and al way s before
going on a long trip.
• If you have the impression your engine consumes excessive
amounts of oi l, we reco mmend that you consult your Audi dealer to
have the cause of your concern properly diagnosed . Keep in mind
that t he accurate measurement of oil consumptio n requ ires great
care and may take some time. Your Audi dealer has instructions
about how t o measure oil cons umpt ion accurately. •
Checking the engine oil level
Vehicle care
Fig. 2 07 Illu strati on of
prin ciple 1: M ark ers on
oil dip sti ck ...

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-Read the engine coolant level in the open coolant expan­
sion
tank => fig. 211. With a cold engine, the coolant level
should be between the "min" and "max" markings. When
the engine is warm, the level may be slightly above the "max" marking.
The location of the coolant expansion tank can be seen in the
engine compartment
illustration=> page 275 .
To obtain an accurate reading, the engine must be sw itched off.
The expansion tank in your vehicle is equipped with an electric
coolant level sensor.
When the coolant level is too low, the warning light in the Auto ­
Check System
=> page 31 will blink until you add coolant and the
level has been restored to normal. Even though there is an electric
coolant level sensor, we still recommend you check the coolant level
from time to time.
Coolant loss
Coolant loss may indicate a leak in the cooling system . In the event
of coolant loss, the cooling system should be inspected immedi­
ately by your authorized Audi dealer . It is not enough merely to add
coolant.
In a
sealed system, losses can occur only if the boiling point of the
coolant is exceeded as a result of overheating.
& WARNING
The cooling system is under pressure and can get very hot. Reduce
the risk of scalding from hot coolant by following these steps.
• Turn off the engine and allow it to cool down.
• Protect your face, hands and arms from escaping fluid and
steam by covering the cap with a large, thick rag.
& WARNING (continued)
• Turn the cap slowly and very carefully in a counter-clockwise
direction while applying light, downward pressure on the top of
the cap.
• To avoid being burned, do not spill antifreeze or coolant on the
exhaust system or hot engine parts. Under certain conditions, the
ethylene glycol in engine coolant can catch fire.
0 Note
Do not add any type of radiator leak sealant to your vehicle's engine
coolant. Adding radiator repair fluid may adversely affect the func ­
tion and performance of your cooling system and could result in damage not covered by your New Vehicle Limited Warranty. •
Adding coolant
Be very careful when adding engine coolant.
Before you check anything in the engine compartment,
always read and heed all WARNINGS => & in "Working in
the engine compartment" on
page 273.
-Turn off the engine.
-Let the engine cool down.
-Place a thick rag over the coolant expansion tank
=> page 281 , fig. 211 and carefully twist the cap counter­
clockwise
=> & .
-Add coolant.
-Twist the cap on again tightly.
Replacement engine coolant must conform to exact spec ifications
=> page 280, "Coolant". If in an emergency coolant additive G12 + is .,,

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Brake f luid
Checking brake fluid level
The brake fluid level c an be checked with a quick glance .
Fig. 212 Engin e
co mp artm ent: B rak e
f lu id rese rvoi r
Before you check a nything in the e ngine compartment,
alway s re ad and he ed all WARNINGS ~ & in "Working in
the engi ne com partment" on
page 273.
- Pull the rubber st rip @ up partially and lift the cover @
slightly~ fig. 212 .
- Read the brake fluid level from the brake fluid reservoi r
@. The brake fluid level must be between the "MIN" and
"MAX" markings.
The brake fluid reservoir is located at the rear partition of the engine
compartment on the le ft side
~ page 275.
The fluid level may drop slightly after some time due to the auto ­
matic adjustment of the brake pads. This is not cause for alarm.
If the brake fluid level fal ls
considerably below the "MIN" mark, the
brake warning/indicator light (U .S . models :
BRAKE, Canadian models:
0) will come on=> page 23 and~ page 31 . Do not continue to
opera te the vehicle. The complete brake system should be thor ­
oughly checked by an authorized Audi dealer or qua lified workshop
and the cause corrected. If the brake fluid level is too low, the brake
warning/indicator light will illuminate . Contact an authorized Audi
dea ler
immedi atel y.•
Changing brake fluid
H ave the brake fluid changed by an experienced techni ­
cian.
Brake fluid absorbs mo isture from the air . If the water content in the
brake fluid is too high, corrosion in the brake system may result
after a period of time. The bo iling point of the brake fluid wil l a lso
decrease considerably and decrease braking performance.
Therefore, the brake fluid must be changed
e ver y tw o year s. Always
use new brake fluid which conforms to Federal Motor Vehic le Stan­
dard "FMVSS 116 DOT
4".
The brake fluid rese rvo ir can be difficult to reach, therefore, we
recommend that you have the brake fluid changed by your autho­
rized
Audi dealer . Your dealer has the correct tools, the right brake
fl uid and the know-how to do this for you.
& WARNING
• Brake fluid is po is o nou s. It m ust be stored only in the clo se d
orig inal container out of the re ach of children!
• Brake f ailure can resu lt from old o r inapp ropriat e brake fluid .
Ob serve the se precaution s:
- Use only brake fl uid that me ets SAE spe cific atio n
J 1703 and
conform s to F ederal Motor Vehicle Standard 11 6. Alway s check
with y our authorized A ud i dealer t o ma ke sure you are u sing
th e c orrect br ake fluid . The correct type of brake fluid i s al so
i ndicated on the brake flu id re ser voir .
..,_

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& WARNING (continued)
-The brake fluid must be new. Heavy use of the brakes can
cause a vapor lock if the brake fluid is left in the system too
long. This can seriously affect the efficiency of the brakes as
well as your safety. This could result in an accident.
0 Note
Brake fluid will damage the paint of your vehicle.
W For the sake of the environment
Because of the problem of proper disposal of brake fluid as well as
the special tools required and the necessary expertise, we recom­
mend that you have the brake fluid changed by your authorized Audi
dealer. •
Battery
General information
Under normal operating conditions, the battery in your Audi does
not need any maintenance. With
high outside temperatures it is
advisable however to check the fluid level at regular intervals
through the transparent battery housing. Also check the fluid level
each time you charge the battery. After charging the battery
~ page 289, you should likewise check the battery acid level.
Have the battery checked when you take your vehicle in for service.
You are well advised to replace a battery that is older than 5 years.
Preserving battery charge on a vehicle not operated
for a long time
Some components of the electrical equipment (for example, the
electronic immobilizer) will keep drawing a low current even when the car is
not running
. This will eventually drain the battery
completely if your vehicle is left sitting for a long period of time
without being driven . To prevent this, either charge the battery
occasionally or disconnect the battery negative (ground) cable.
Winter operation
During the winter months, battery capacity tends to decrease as
temperatures drop . This is because more power is also consumed
while starting, and the headlights, rear window defogger, etc., are
used more often.
Avoid unnecessary power consumpt ion, particularly in city traff ic or
when traveling only short distances. Let your authorized Audi dealer
check the capacity of the vehicle battery before winter sets in
~ page 289. A well charged battery will not only prevent starting
problems when the weather is cold, but will also last longer.
[ i] Tips
If your vehicle is left standing for several weeks at extremely low
temperatures, the vehicle battery should be removed and stored
where it will not freeze. This will prevent it from being damaged and
having to be replaced. •
Location of the vehicle battery
The vehicle battery is located in the plenum chamber at the back of
the engine
compartment~ page 275.
The positive(+) battery terminal is protected by a plastic cover. This cover must be removed to access to the positive(+) terminal when
connecting jumper cables to start the engine .
& WARNING
Before you check anything in the engine compartment, always
read and heed all WARNINGS
~ & in "Working in the engine
compartment" on
page 273. •
Vehicle care