2008 AUDI A4 cooling

Contents 2ContentsNotes on this Owner's
Manual
. . . . . . . . . . . . . . . . . . . . . .
Controls
. . . . . . . . . . . . . . . . . . . . .
Controls and displays
. . . . . . . . . .
Overview . . . . . . . . . . . . . . . . . . . . . .
Instruments and
warning/indicator lamps
. . . . . . .
Instruments . . . . . . . . . . . . . . . . . . . .
Fuel gauge . . . . . . . . . . . . . . . . . . . . .
Warning and indicator lamps . . . . .
Driver information system
. . . . . .
Introduction . . . . . . . . . . . . . . . . . . . .
On-board computer . . . . . . . . . . . . .
Speed warning function . . . . . . . . .
Auto-check control . . . . . . . . . . . . . .
Tyre pressure monitoring system .
Doors and windows
. . . . . . . . . . . .
Central locking system . . . . . . . . . .
Boot lid . . . . . . . . . . . . . . . . . . . . . . . .
Child-proof catches . . . . . . . . . . . . .
Electric windows . . . . . . . . . . . . . . .
Sun roof . . . . . . . . . . . . . . . . . . . . . . .
Lights and vision
. . . . . . . . . . . . . . .
Lights . . . . . . . . . . . . . . . . . . . . . . . . .
Interior lights . . . . . . . . . . . . . . . . . . .Clear vision . . . . . . . . . . . . . . . . . . . .
Windscreen wipers . . . . . . . . . . . . .
Rear-view mirrors . . . . . . . . . . . . . .
Digital compass . . . . . . . . . . . . . . . .
Seats and storage
. . . . . . . . . . . . .
Manual adjustment of front seats
Electric adjustment of front seats
Seat memory . . . . . . . . . . . . . . . . . .
Head restraints . . . . . . . . . . . . . . . .
Front armrest . . . . . . . . . . . . . . . . . .
Luggage compartment . . . . . . . . .
Roof carrier . . . . . . . . . . . . . . . . . . . .
Roof load . . . . . . . . . . . . . . . . . . . . .
Cup holders . . . . . . . . . . . . . . . . . . .
Ashtrays . . . . . . . . . . . . . . . . . . . . . .
Cigarette lighter and electrical
sockets . . . . . . . . . . . . . . . . . . . . . . .
On-board 230 Volt Euro socket . . .
Storage compartments . . . . . . . . .
Heating and cooling
. . . . . . . . . . .
Deluxe automatic air conditioner .
Deluxe automatic air conditioner -
basic settings . . . . . . . . . . . . . . . . . .
Deluxe automatic air conditioner
plus . . . . . . . . . . . . . . . . . . . . . . . . . .
Deluxe automatic air conditioner
plus - basic settings . . . . . . . . . . . .
Auxiliary heating and auxiliary
ventilation . . . . . . . . . . . . . . . . . . . . .
Seat heating . . . . . . . . . . . . . . . . . . .
Driving
. . . . . . . . . . . . . . . . . . . . . . . . .
Steering . . . . . . . . . . . . . . . . . . . . . . .
Ignition lock . . . . . . . . . . . . . . . . . . .
Starting and stopping the engine
with the advanced key . . . . . . . . . . Electro-mechanical parking brake
Cruise control system . . . . . . . . . . .
adaptive cruise control (ACC)
. .
Speed and distance control system
Driver messages . . . . . . . . . . . . . . .
System limitations . . . . . . . . . . . . . .
Audi braking guard . . . . . . . . . . . . .
Audi lane assist
. . . . . . . . . . . . . . . .
Audi lane assist . . . . . . . . . . . . . . . .
Audi side assist
. . . . . . . . . . . . . . . .
Lane change assist feature . . . . . .
Notes . . . . . . . . . . . . . . . . . . . . . . . . .
Audi drive select
. . . . . . . . . . . . . . .
Adjusting the vehicle set-up . . . . .
Automatic gearbox
. . . . . . . . . . . . .
multitronic®, tiptronic (6-speed
gearbox) . . . . . . . . . . . . . . . . . . . . . . .
Parking aid
. . . . . . . . . . . . . . . . . . . . .
General notes . . . . . . . . . . . . . . . . . .
Audi parking system . . . . . . . . . . . .
Audi parking system plus . . . . . . . .
Audi parking system advanced . . .
Switching display and acoustic
signals on and off . . . . . . . . . . . . . .
Towing bracket . . . . . . . . . . . . . . . . .
Error messages . . . . . . . . . . . . . . . . .
HomeLink
. . . . . . . . . . . . . . . . . . . . . .
Universal transmitter . . . . . . . . . . . . 5
7
9
9
11
11
14
15
21
21
25
28
30
39
42
42
51
53
53
55
57
57
6364
65
68
71
73
73
74
75
77
78
79
83
84
85
86
87
89
90
93
93
100
101
109
110
114
116
116
116
118121
125
128
128
134
140
142
145
145
149
149
156
159
159
162
162
169
169
169
170
171
177
177
178
179
179
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Contents3
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Safety
. . . . . . . . . . . . . . . . . . . . . . .
Safe driving
. . . . . . . . . . . . . . . . . . . .
General notes . . . . . . . . . . . . . . . . . .
Correct sitting positions . . . . . . . .
Pedal area . . . . . . . . . . . . . . . . . . . . .
Stowing luggage safely . . . . . . . . .
Seat belts
. . . . . . . . . . . . . . . . . . . . . .
Why is it so important to use seat
belts? . . . . . . . . . . . . . . . . . . . . . . . . .
Forces acting in a collision . . . . . .
How to wear seat belts properly .
Belt tensioners . . . . . . . . . . . . . . . . .
Airbag system
. . . . . . . . . . . . . . . . .
Description of airbag system . . . .
Front airbags . . . . . . . . . . . . . . . . . .
Side airbags . . . . . . . . . . . . . . . . . . .
Head-protection airbags
(sideguard) . . . . . . . . . . . . . . . . . . . .
Deactivating the front passenger's
airbag via the key-operated switch
Child safety
. . . . . . . . . . . . . . . . . . . .
Points to remember if children are
travelling in the car . . . . . . . . . . . . .
Child safety seats . . . . . . . . . . . . . .
Fitting child safety seats . . . . . . . .
Driving tips
. . . . . . . . . . . . . . . .
Intelligent technology
. . . . . . . . . .
Electronic stabilisation program
(ESP) . . . . . . . . . . . . . . . . . . . . . . . . . .
Brakes . . . . . . . . . . . . . . . . . . . . . . . . .
Power steering (servotronic) . . . . .
Four-wheel drive (quattro®) . . . . . .
Power management . . . . . . . . . . . .
Your vehicle and the
environment
. . . . . . . . . . . . . . . . . . .
Running in . . . . . . . . . . . . . . . . . . . . .
Emission control systems . . . . . . .
How to improve economy and
minimise pollution . . . . . . . . . . . . . .
Environmental compatibility . . . . .
Towing a trailer
. . . . . . . . . . . . . . . .
Driving the vehicle with a trailer or
caravan . . . . . . . . . . . . . . . . . . . . . . .
Removable towing bracket . . . . . .
General maintenance
. . .
Care of vehicle and cleaning
. . .
General notes . . . . . . . . . . . . . . . . . .
Care of exterior . . . . . . . . . . . . . . . . .
Care of interior . . . . . . . . . . . . . . . . .
Fuel and filling the tank
. . . . . . . .
Petrol . . . . . . . . . . . . . . . . . . . . . . . . . .
Diesel . . . . . . . . . . . . . . . . . . . . . . . . .
Filling the tank . . . . . . . . . . . . . . . . . .
Checking and topping up fluidsBonnet . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment layout . . . . . .
Engine oil . . . . . . . . . . . . . . . . . . . . . .
Cooling system . . . . . . . . . . . . . . . . .
Brake fluid . . . . . . . . . . . . . . . . . . . . .
Battery . . . . . . . . . . . . . . . . . . . . . . . .
Windscreen washer . . . . . . . . . . . . .Wheels and tyres
. . . . . . . . . . . . . . .
Wheels . . . . . . . . . . . . . . . . . . . . . . . .
Run flat tyres . . . . . . . . . . . . . . . . . . .
Accessories and modifications
to the vehicle
. . . . . . . . . . . . . . . . . . .
Accessories and replacement
parts . . . . . . . . . . . . . . . . . . . . . . . . . .
Modifications . . . . . . . . . . . . . . . . . .
Radio transmitters and business
equipment . . . . . . . . . . . . . . . . . . . . . 185
186
186
188
191
192
194
194
195
197
199
201
201
203
205
207
208
210
210
213
216221
222
222
224
225
226
226
229
229
229
229
231
232
232
235243
244
244
244
247
251
251
251
252
254
254
256
257
260
262
263
267
268
268
274
277
277
277
278
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Instruments and warning/indicator lamps 12Warning symbol in instrument cluster

If the symbol
 lights up in the display, this means that either the
coolant temperature is too high or the coolant level is too low
⇒page 33.
If the needle is at the top end of the dial, this means the coolant
temperature is too high. Stop the vehicle, switch off the engine and
wait for it to cool down. If the warning lamp starts flashing again
after just a short distance, contact a qualified workshop.
WARNING
•
Before opening the bonnet and checking the coolant level,
please observe the warning information on ⇒page 255, “Working
on components in the engine compartment”.
•
Never open the bonnet if you can see or hear steam or coolant
escaping from the engine compartment; there is a risk of being
scalded. Wait until you can no longer see or hear escaping steam
or coolant.Caution
•
Additional lights and other accessories in front of the air inlet
reduce the cooling effect of the radiator. At high outside tempera-
tures and high engine loads, there is a risk of the engine over-
heating.
•
The front spoiler also ensures proper distribution of the cooling
air when the vehicle is moving. If the spoiler is damaged this can
reduce the cooling effect, which could cause the engine to overheat.
You should obtain professional assistance.
Rev counter
The rev counter indicates the number of engine revolu-
tions per minute.You should select a lower gear if the engine speed drops below
1500 rpm. The start of the red zone on the dial indicates the
maximum engine speed which may be used briefly when the engine
is warm and after it has been run in properly. However, it is advisable
to change up a gear or move the selector lever to “D” (or lift your
foot off the accelerator) before the needle reaches the red zone.
Caution
Never allow the rev counter needle ⇒page 11, fig. 2 to go into
the red zone on the dial for more than a very brief period: there is a
risk of damaging the engine. The start of the red zone on the dial is
different for some engine versions.
For the sake of the environment
Changing up a gear early will help you to save fuel and minimise
engine noise.
button
This button has a number of different functions.
A2
SET
Fig. 3 Instrument
cluster: SET button
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Driver information system33
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data easily when braking. This could cause the tail of the vehicle to skid
sideways. Drive carefully to the nearest qualified workshop and
have the fault rectified.
Note
The warning lamp
 in the instrument cluster will start flashing as
well if there is a fault in the brake system.
Fault in the cooling system

Faults in the cooling system must be rectified immedi-
ately.If the
 symbol flashes in the display, this means that
either the coolant temperature is too high or the coolant
level is too low. The symbol is accompanied by a driver
message giving you more information about the fault. This
message will disappear after about 5 seconds, but you can
call it up again at any time by pressing the button:
Switch off engine, check coolant level
–Stop the vehicle.
– Switch off the engine.
– Check the coolant level ⇒page 261.
– Add more coolant if necessary ⇒page 261.
– Wait for the symbol to go out before driving on.
– Obtain professional assistance if necessary.
If the coolant level is correct, the overheating may be caused by a
malfunction of the radiator fan.If the alternator warning lamp lights up as well ⇒page 32, it is
possible that the drive belt has broken.
WARNING
•
If your vehicle should break down for technical reasons, stop it
at a safe distance away from moving traffic, switch off the engine
and turn on the hazard warning lights ⇒page 61, “Hazard
warning lights ”.
•
Never open the bonnet if you can see or hear steam or coolant
escaping from the engine compartment; there is a risk of being
scalded. Wait until you can no longer see or hear escaping steam
or coolant.
•
The engine compartment of any motor vehicle is a dangerous
place. Before carrying out any work in the engine compartment,
switch off the engine and allow it to cool down. Please observe the
important safety warnings ⇒page 255, “Working on components
in the engine compartment”.Caution
Do not drive on if the symbol
 has come on to indicate a fault in
the cooling system, otherwise there is a risk of damaging the
engine.
Engine oil pressure too low

If the engine oil pressure is too low the fault must be recti-
fied immediately.If the

symbol flashes in the display, the oil pressure is
too low. The symbol is accompanied by a driver message
giving you more information about the fault. This message
WARNING (continued)
SET
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Heating and cooling93
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Heating and coolingDeluxe automatic air conditionerApplies to vehicles: with deluxe automatic air conditionerDescription
The air conditioner can be used to set a comfortable inte-
rior temperature in the vehicle.The air conditioner provides heating and ventilation and also cools
and dehumidifies the air inside the vehicle.
The air conditioner is fully automatic and will maintain the desired
temperature at a constant level. To achieve this, the temperature of
the air supplied to the interior, the blower speed (volume of air
delivery) and the air distribution are regulated automatically. The
system also allows for the effect of strong sunlight, so there is no
need for manual adjustment. For these reasons it is advisable to use
the automatic mode for the comfort of all the passengers in virtually
all conditions throughout the year ⇒page 95.
Please note:
The humidity of the air is automatically reduced when the system
cools the interior of the vehicle. This helps to prevent condensation
on the windows.
If the humidity and temperature outside the vehicle are high,
condensation can drip off the evaporator in the air cooling system
and form a pool underneath the vehicle. This is normal and does not
indicate a leak.
If the outside temperature is low, the blower normally only switches
to a higher speed once the coolant has warmed up sufficiently (this
does not apply to the defrost setting).
In order to achieve maximum engine power, the air conditioner
compressor is temporarily switched off when pulling away from a
standstill with full throttle.The compressor also switches off if the coolant temperature is
excessively high, to ensure adequate engine cooling under extreme
loads.
Pollution filter
The pollution filter (a particle filter) serves as a barrier against impu-
rities in the outside air, including dust and pollen, and odours. The
air is also filtered when the air recirculation mode is activated.
For the air conditioner to work with maximum efficiency, the pollu-
tion filter element must be replaced at the intervals specified in the
Service Schedule.
If the vehicle is driven in areas with a high level of air pollution and
the filter is no longer fully effective, it may be necessary to change
the filter element more frequently.
Key-coded settings
The currently selected air conditioner settings are automatically
stored and assigned to the remote control key.
Power management
To prevent the battery from becoming discharged and to maintain
the necessary power level, the system will temporarily shut off the
electrical components that are using a lot of power, or reduce the
current they are consuming ⇒page 226. Heating systems in partic-
ular use a large amount of electrical power. If you notice, for
instance, that the rear window heater is not working, it may have
been temporarily switched off by the power management function,
or regulated to a lower heat output. These systems will be available
again as soon as sufficient electrical power is available.
WARNING
For safety reasons it is important that all the windows are kept
free of ice, snow and condensation. These can cause poor visibility
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Heating and cooling 94and lead to an accident. Please familiarise yourself with the oper-
ating controls for the air conditioner, including the demist/defrost
functions for the windows.
Caution
•
If you suspect that the air conditioner is damaged, switch it off
to prevent further damage and have the system checked by a quali-
fied workshop.
•
Repairs to the Audi air conditioner require specialist knowledge
and special tools. For this reason, please contact a qualified work-
shop if the system is not working properly.Note
•
Keep the air intake slots in front of the windscreen clear of snow,
ice and leaves to ensure unimpaired heating and cooling, and to
prevent the windows misting over.
•
The air from the outlets flows through the passenger compart-
ment and out through the slots at the rear of the vehicle. Do not
cover these slots with clothing or other objects.
•
The air conditioner operates most effectively with the windows
and the tilting panorama roof* closed. However, if the vehicle has
heated up after standing in the sun for some time, the air inside can
be cooled more quickly by opening the windows for a short time.
Applies to vehicles: with deluxe automatic air conditionerControls
The controls for the air conditioner at a glance.Fig. 103 Controls for deluxe automatic air conditionerThe functions can be set by turning the rotary control and are
switched on and off by briefly pressing the buttons. The LEDs in the
buttons light up when the function is switched on.
WARNING (continued)
Button(s)
Function
Page
Switching on and off
⇒page 95
Automatic mode
⇒page 95
Rotary control
a)
Temperature selection
⇒page 96
Blower
⇒page 96
Air recirculation mode
⇒page 97
OFFAUTO
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Heating and cooling95
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
The grille on the control console ⇒page 94, fig. 103 must be kept
free. Please ensure that it is not covered by stickers or similar. Meas-
uring sensors are located behind it.Applies to vehicles: with deluxe automatic air conditionerSwitching on and offSwitching on air conditioner
– Press the button briefly, or
– Press the button.
Switching off air conditioner
– Press the button to switch off the air conditioner
and cut off the supply of fresh air from outside the
vehicle.The air conditioner will switch on again if one of the control buttons
is pressed.
Applies to vehicles: with deluxe automatic air conditionerAutomatic mode
The standard operating mode for all seasons.Switching on automatic mode
– Select a temperature between +16 °C (60 °F) and +28 °C
(84 °F).
– Press the button.The automatic mode maintains a constant temperature inside the
vehicle and dehumidifies the air. Air temperature, air delivery and
air distribution are regulated automatically to reach the desired
interior temperature as quickly as possible, and then to maintain
this temperature. The system automatically compensates for any
variations in the outside temperature and for the effect of direct
sunlight.
The automatic temperature regulation only operates at temperature
settings between +16 °C and +28 °C. If a temperature below +16 °C
is selected, LO appears on the display. If a temperature above +28 °C
is selected, the display will show HI. In the two extreme settings the
air conditioner operates continuously with maximum cooling or
heating output, and the temperature is not regulated
automatically.

Air distribution
⇒page 97
Defrosting windows
⇒page 98
Heated rear window
⇒page 98
Switching air cooling
on/off
⇒page 98
Seat heating
⇒page 114
a)The rotary control is also used to adjust the blower speed, air distribution
and seat heating.Button(s)
Function
Page
AC
OFFAUTOOFF
AUTO
AUTO
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Heating and cooling 96Applies to vehicles: with deluxe automatic air conditionerTemperature selection– Turn the rotary control anti-clockwise to reduce the
temperature or clockwise to increase the temperature
⇒fig. 104.The temperature setting will be shown on the screen ⇒fig. 105 for
a few seconds if the sound system or MMI* is switched on.
Applies to vehicles: with deluxe automatic air conditionerBlower

The automatically selected blower speed can be reduced
or increased manually if required.– Press the button for the blower .
– Turn the rotary control to set the blower to the desired
speed (and regulate the volume of air delivery).We recommend keeping the blower running at a low setting when
driving slowly.
To prevent fumes or unpleasant smells from entering the vehicle,
switch to the air recirculation mode by pressing the button.
Fig. 104 Rotary control
for temperature selec-
tionFig. 105 Display:
Temperature setting
Fig. 106 Blower
button and rotary
controlFig. 107 Display:
Blower setting


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