check engine light AUDI A4 CABRIOLET 2009 Owner's Manual

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the form of Service or Repair Orders that all scheduled maintenance
was performed in a timely 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 provide effective lubrication and cooling of internal
engine components , all internal combustion engines consume a
certain amount of oil. Oil consumption varies from engine to engine
and may change significantly over the life of the engine. Typically,
engines with a specified break -in period (see~
page 219) consume
more oil during the break-in period than they consume after oil
consumption has stabilized.
Under normal conditions, the rate of oil consumption depends on
the quality and viscosity of the oil, the RPM (revolutions per minute)
at which the engine is operated, the ambient temperature and road
conditions. Further factors are the amount of oil dilution from water
condensation or fuel residue and the oxidation level of the oil. As
any engine is subject to wear as mileage builds up , the oil consump­
tion may increase over time until replacement of worn components
may become necessary .
With all these variables coming into play, no standard rate of oil
consumption can be established or specified. There is no alternative
to regular and frequent checking of the oil level, see
Note.
If the yellow engine oil level warning symbol in the instrument
cluster lights up, you should check the oil level as soon as
possible
with the oil dipstick~ page 254. Top off the oil at your
earliest convenience~
page 255.
& WARNING
Before you check anything in the engine compartment, always
read and heed all WARNINGS
~ & in "Working in the engine
compartment" on
page 250.
0 Note
Driving with an insufficient oil level is likely to cause severe damage
to the engine.
[ i] Tips
• The oil pressure warning display 't!::r. is not an indicator of the oil
level. Do not rely on it. Instead, check the oil level in your engine at
regular intervals, preferably each time you refuel, and always before
going on a long trip.
• If you have the impression your engine consumes excessive
amounts of oil, we recommend that you consult your Audi dealer to
have the cause of your concern properly diagnosed . Keep in mind
that the accurate measurement of oil consumption requires great
care and may take some time . Your Audi dealer has instructions
about how to measure oil consumption accurately. •
Checking the engine oil level
Fig. 198 Illustration of
principle 1: Markers on
oil dipstick ..,_

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0 Note
• Before winter sets in, have the coolant checked to see if the
coolant additive in your vehicle is sufficient to meet the climate
conditions. This is especially important if you live in a region where
the winter is extremely cold . If necessary, increase the proportion of
coolant additive to 60% .
• When adding coolant additive to your cooling system,
remember:
-We recommend using only coolant additive G12+ + (check the
label) for your vehicle. This coolant additive is available at autho­
rized Audi dealers. Other types of antifreeze can significantly
reduce corrosion protection . The resulting corrosion can cause a
loss of coolant and serious engine damage.
• Do not add any type of radiator leak sealant to your vehicle's
engine coolant. Adding radiator repair fluid may adversely affect the
function and performance of your cooling system and could result
in damage not
covered by your New Vehicle Limited Warranty. •
Checking the engine coolant level
The engine coolant level can be checked with a quick
glance.
Fig . 202 Engine
compartment: Coolant
expansion tank
Before you check anything in the engine compartment,
always read and heed all WARNINGS~ & in "Working in
the engine compartment" on
page 250.
Turn off the ignition.
- Let the eng ine cool down.
Place a thick rag over the coolant expansion tank
~ fig. 202 and carefully twist the cap counter-clockwise
~& .
Read the engine coolant level in the open coolant expan­
sion tank~ fig. 202. 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 252.
To obtain an accurate reading , the engine must be switched off .
The expansion tank in your vehicle is equipped with an electric
coolant level sensor.
When the coolant l evel 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. ..,.

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•
& WARNING
The cool ing system i s under pre ssure and can get very hot . Redu ce
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 cover ing the cap with a large , thick rag .
• Turn the cap slowly and very carefully
in a counter -clockwi se
dire ction 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 radiat or repa ir fl uid may adversely affect t he func ­
tion and performance of your coo ling system and could resu lt in
damage not cove red by y our New Vehicle Limi ted Wa rran ty .•
Adding coolant
B e very c are ful when addi ng engi ne cool ant.
Be fore you check a nything in the e ng ine comp artmen t,
always read and heed all WARNINGS=> & in "Work ing in
t h e eng ine compa rtment" on
page 250 .
-Tur n off th e engine.
- Le t th e eng in e co ol d ow n.
- Place a t hick rag over the coo la nt expansio n tank
~ page 258 , fig. 202 an d carefully tw is t th e cap coun te r­
cl ockw ise
~ & .
Add co o lant .
- Twist the cap on aga in
tig htly .
Replacement engine coolant must conform to exact specifications
~ page 257 , "C oola nt". Even in an eme rgency, if co ola nt addi tive
G 12 ++, G12+ or G1 2 is not availab le, do
not use a different additive .
Us e pla in wate r instead until you can ge t the co rrect add itive and
can res tor e th e correc t ra tio. T his shou ld be don e as soon as
pos sible.
If y ou have los t a co nsid era ble amount of coo la nt, t hen y ou should
add cold antifreeze and cold water only when the engine is cold.
A lways use
new engine c oo la nt whe n refil ling .
Do not fill coola nt a bove the "M AX" mark. Excess coo lant w ill be
forced out through the pressure relief va lve in the cap when the
eng ine beco mes hot.
& WARNING
• The cooling system i s 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 .
- 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 exhau st system or hot engine parts. Under certain condi ­
tions, the ethylene glycol in engine coolant can catch fire .
• Antifreeze is poisonous . Always store antifreeze in its original
container and well out of the reach of children .
• If you drain the coolant , it must be caught and safely stored in
a proper container clearly marked "poison ". _,.
Ve hic le care

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0 Note
• Coolant pollutes the environment and could cause an engine
fire. Excess coolant will be forced out through the pressure relief
valve in the cap when the engine becomes hot.
• If, in an emergency, only water can be added, the correct ratio
between water and antifreeze~
page 257must be restored as soon
as possible.
<£> For the sake of the environment
Drained coolant should not be reused. Always dispose of used
coolant while observing all environmental regulations. •
Radiator fan
The radiator fan switches on automatically by itself.
The radiator fan is driven by the engine via the V-belt. The viscous
clutch regulates the speed of the fan according to the temperature
of the coolant.
An auxiliary electric radiator fan* switches on and off depending on coolant temperature and other vehicle operating conditions.
After you switch the engine off, the auxiliary fan can continue running for up to 10 minutes - even with the ignition off. It can even
switch on again later by itself~&, if
• the temperature of the engine coolant rises due to the heat
build -up from the engine in the engine compartment, or
• the engine compartment heats up because the vehicle is parked
in intense sunlight.
& WARNING
• To reduce the risk of personal injury never touch the radiator
fan .
_& WARNING (continued)
• The auxiliary electric fan is temperature controlled and can
switch on suddenly even when the engine is not running .
• The auxiliary radiator fan switches on automatically when the
engine coolant reaches a certain temperature and will continue to
run until the coolant temperature drops. •
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a quick glance.
Fig. 203 Engine
compartment: Brake
fluid reservoir
Before you check anything in the engine compartment,
always read and heed all WARNINGS:::::, & in "Working in
the engine compartment" on
page 250.
Pull the rubber strip@ up partially and lift the cover @
slightly :::::, fig. 203.
- Read the brake fluid level from the brake fluid reservoir
©. The brake fluid level must be between the "MIN" and
"MA X" markings. _..

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•
The brake fluid reservoir is located at the rear partition of the engine
compartment on the left side~
page 252 .
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 falls
considerably below the "MIN" mark, the
brake warning/indicator light (U .S. models :
BRAKE, Canadian models :
(CD) ) wi ll come on
~ page 23 and ~ page 30. Do not continue to
operate the vehicle. The complete brake system should be thor ­
oughly checked by an authorized Audi dealer or qualified 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
immediately .•
Changing brake fluid
Have the brake fluid changed by an experienced techni­
cian.
Brake fluid absorbs moisture 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 boiling point of the brake fluid wil l also
decrease considerably and decrease braking performance.
Therefore, the brake fluid must be changed
every two years. Always
use new brake fluid which conforms to Federa l Motor Vehic le Stan­
dard "FMVSS 116 DOT 4".
The brake fluid reservoir 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
fluid and the know -how to do this for you.
& WARNING
• Brake fluid is poisonous. It must be stored only in the closed
original container out of the reach of children!
& WARNING (continued)
• Brake failure can result from old or inappropriate brake fluid.
Observe these precautions :
- Use only brake fluid that meets SAE specification
J 1703 and
conforms to Federal Motor Vehicle Standard 116. Always check
with your authorized Audi dealer to make sure you are using
the correct brake fluid. The correct type of brake fluid is also
indicated on the brake fluid reservoir .
- 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 wil l damage the paint of your vehicle .
ci> 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
advisab le 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 265, you shou ld likewise check the battery acid level. ...
Vehic le care

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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.
Disconnecting the battery terminals
Some vehicle functions (power window regulators, for example) are
lost if the battery terminals are disconnected . Th ese functions have
to be relearned after the battery terminals are connected again. To
prevent this, the battery should only be disconnected from the
vehicle electrical system when absolutely necessary for repairs .
Vehicles not driven for long periods
If you are going to let your vehicle stand for a long time and not
drive it, you should remember there are electrical components
which are still functioning and they will draw energy from the
battery and drain it, for example, the engine immobilizer. To prevent
this, you can either charge the battery occasionally to keep it in
good working condition or you can disconnect the negative cable
on the battery.
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 consumption, particularly in city traffic or
when traveling only short distances . Let your authorized Audi dea ler
check the capacity of the vehicle battery before winter sets in
=>
page 265 . A we ll charged battery wil l not only prevent starting
problems when the weather is cold, but will also last longer.
Replacing battery
The new battery must have the same capacity, voltage (12 volts),
amperage, construction and plug sea ling, as the origina l battery.
Specifications are listed on the battery housing. Batteries specially
developed by Audi fulfill the maintenance, output, and safety
requirements. When installing the battery, make sure the ignition and all electrical
consumers are switched off=>
0.
We recommend that you use maintenance -free or cyc le-resis­
tant/leak-proof
batteries according to the standards TL 825 06 (from
December 1997) and VW 7 50 73 (from August 2001).
Replacing the battery should be carried by a qualified workshop.
Please follow the instructions on the battery cover.
0 Note
• All work on the battery requires technical knowledge. Please
contact an Audi dealership or another authorized facility for ques­
tions about the battery -danger of acid burns and exp losion hazard!
• Make sure the ventilation hose on the side of the battery is
connected, otherwise fumes or battery acid can leak out.
• Battery holder and terminals always have to be secured correctly.
• Before all work on the battery follow the
warnings below=> & in
"Working on the battery" on
page 263.
Because of the problem of proper disposal of a battery, we recom­
mend your authorized Audi dealer change the battery for you.
Batteries contain sulfuric acid and lead and must always be
disposed of properly in compliance with all environmental regula ­
tions . Disposing of vehicle batteries improperly is very dangerous to
the environment . Make sure that the removed battery cannot over ­
balance, otherwise sulfuric acid might escape!
[ 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.•

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Working on the battery
Be especially careful when working on or near the battery.
•·•·•·•
Fig. 204 Engine
compartment, plenum
chamber : battery cover
Before you check anything in the engine compartment,
always read and heed all WARNINGS=>
& in "Working in
the engine compartment" on
page 250.
Removing the cover
-Push the cover in the direction of the arrow => fig. 204.
Always heed the safety warnings, when working on the vehicle
battery or the vehicle electrical system to prevent injury.
The following WARNINGS are very important when
working on the battery:
Always heed the following WARNING SYMBOLS and safety pre ­
cautions when working on the battery .
®
Always wear eye protection.
Battery acid contains sulfuric acid. Always wear
gloves and eye protection.
No
- sparks
- flames
- smoking.
When a battery is charged, it produces hydrogen
gas which is explosive and could cause personal
injury.
Always keep the battery well out of reach of chil­
dren.
& WARNING
Whenever working on the battery or on the electrical system,
there is the risk of injury, accident and even fire. Read and heed the
following WARNINGS:
• Always wear eye protection. Do not let battery acid or any lead
particles get on your skin or clothing. Shield your eyes. Explosive
gases can cause blindness or other injury.
• Battery acid contains sulfuric acid. Sulfuric acid can cause
blindness and severe burns .
- Always wear gloves and eye protection. Do not tilt the battery because acid could leak out of the ventilation openings .
- If you get battery acid in your eyes or on your skin, immedi ­
ately rinse with cold water for several minutes and get medical
attention.
- If you should ingest any battery acid, seek medical attention
immediately.
• Do not expose the battery to an open flame , electric sparks or
an open light.
• Do not smoke.
• Do not interchange the positive and negative cables .
• When working on the battery, be sure not to short-circuit the
terminals with tools or other metal objects. This would cause the .,,.
Vehic le care irechnical data

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& WARNING (continued )
battery to heat up very q uickly, which could lead to damage or
explo sion and per sonal injury .
• When a battery is charged , it produces hydrogen gas whic h i s
explo sive and could cause per son al injury .
• Always keep the battery well out of the re ach of children.
• Before work i s done on the electrical system , di sconne ct the
negative ground cable .
• Before per forming any work on the ele ctri cal system , switch off
the engine and ignition as well as any electrical equipment. The
negative cable on the battery must be disconnected .
If you are just
going to replace a light bulb , then it is enough to switch off the
light s.
• Before disconnecting the battery , switch off the anti -theft
alarm system! Otherw ise you will set off the alarm .
• When di sconne cting the battery , fir st di sconnect the negative
c able and then the positive cable .
• Before reconnecting the battery , make sure all electrical
c onsumers are sw itched off . Reconnect the posit ive cable first and
then the negative cable. Never interchange the cables -this could
start a fire !
• Never charge a frozen or a thawed -out battery. It could
e xplode! If a battery has frozen , then it must be replaced. A
discharged batte ry can freeze over at 32 °F (0 °C ).
• Make sure the vent hose is always attached to the opening on
the side of the battery.
• Never use batteries which are damaged . There is the danger of
an explosion! Alway s replace a damaged battery.
& WARNING
California Propo sition 65 Warning :
& WARNING (continued )
• Battery post s, terminals and related accessories contain le ad
and lead compounds , chemicals known to the State of California
to cause can cer and reproduct ive problems . Wash hand s after
handling .
0 Note
• Do not disco nnect t he vehicle battery when the igni tion is
switched on or when the engine is running , otherwise, you wi ll
damage e le ctronic c ompone nts in the electrical syst em.
• I f your vehicle is going to stand for a long period of time without
being dr iven, protect the battery from "freezing" otherwise it wil l be
damaged and wi ll then have to be replaced .•
Checking the battery acid level
T he aci d l evel of a co nv enti onal ba ttery c an be c hecke d
vis ually.
·•
Fig . 2 05 Engine
c ompartment : Battery
w it h o pen b atter y
compartment cover
T he leve l of acid inside the b atte ry is vis ib le th rough the
case a t the fo nt. Ac id le ve l shou ld be ex actly at t he " max "
m ark or v ery clo se belo w it.
~

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Windshield /headlight washer
reservoir
Fig . 206 Engine
compartment : wind­
shield washer fluid
container
The windshield and headlight washer* container is located
on the left side of the engine compartment
~ fig. 206. The
~ symbol is on the cap the of the windshield washer fluid
container.
- Before you check anything in the engine compartment,
always
read and heed all WARNINGS~ & in "Working
in the engine compartment" on
page 250.
-Lift the filler cap tongue to add washer fluid. You can fill
the container to the top.
- Press the cap back onto the filler neck after filling the
container .
You can find the reservoir capacity in the table in~ page 314.
To prevent lime residue from building up on the spray jets , use
dis tilled water when refilling . Always add a glass cleaner solution
(with frost protection in the winter).
(D Note
Do not use engine coolant antifreeze or any other solution that can
damage the vehicle paint. •

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& WARNING (continued)
• Before you check anything in the engine compartment, always
read and heed all WARNINGS~ page 242, "Engine compartment".
0 Note
• Applying a higher voltage booster battery will cause expensive
damage to sensitive electronic components, such as control units,
relays, radio, etc .
• There must be no electrical contact between the vehicles as
otherwise current could already start to flow as soon as the positive
(+) terminals are connected.
[ i] Tips
The discharged battery must be properly connected to the vehicle's
electrical system. •
Use of jumper cables
Make sure to connect the jumper cable clamps in exactly
the order described below!
Fig. 225 Jump·
starting with the
battery of another
vehicle : A -discharged
vehicle battery, B -
booster battery
Vehicle with discharged battery:
- Turn off lights and accessories, move lever of automatic
transmission to
N (Neutral) or P (Park) and set parking
brake.
Connect POSITIVE (+) to POSITIVE (+) (red)
1. Connect clamp of plus cable to positive(+) terminal G)
~ fig. 225 of discharged vehicle battery@.
2. Connect clamp on opposite end of cable to positive(+)
terminal
® of booster battery@.
Connect NEGATIVE (-) to NEGATIVE (-) (black)
3. Connect clamp of minus cable (black) to negative( -)
terminal
0 of booster battery@.
4. Connect clamp on opposite end of negative cable to the
negative( -) terminal © of the discharged vehicle battery
@.
- Check that all screw plugs on the battery cells are
screwed in firmly. If not, tighten plugs prior to
connecting clamp on negative battery terminal.
Starting the engine
- Start the engine of the vehicle with the booster battery.
Run the engine at a moderate speed.
- Start engine with discharged vehicle battery in the usual
manner.
- If the engine fails to start: do not keep the starter
cranking for longer than 10 seconds. Wait for about 30
seconds and then try again. .,,.
~ehicle care Do-it-yourse lf service Technical data