2008 AUDI A4 coolant temperature

Instruments and warning/indicator lamps11
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Instruments and warning/indicator lampsInstrumentsInstrument cluster overview
The instrument cluster is the driver's information centre.Fig. 2 Overview of instrument cluster
Coolant temperature gauge . . . . . . . . . . . . . . . . . . . . . .
Rev counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warning and indicator lamps . . . . . . . . . . . . . . . . . . . . .
button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Display
−Driver information system . . . . . . . . . . . . . . . . . . . . .
−Date and time display . . . . . . . . . . . . . . . . . . . . . . . . .
−Mileage recorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reset button for trip recorder . . . . . . . . . . . . . . . . . . . . Speedometer
Fuel gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note
•
The needles in the instrument cluster will sweep across the dials
when you switch on the ignition.
•
The instrument lighting (illumination of dials and needles) is
switched on when the ignition is on and the vehicle's lights are off.
The instrument lighting is dimmed automatically as the daylight
starts to fade. This function is intended to remind the driver to
switch on the dipped-beam headlights in good time when light
conditions become poor.
Coolant temperature gaugeThe coolant temperature gauge ⇒fig. 2 only works when the
ignition is switched on. In order to avoid possible damage to the
engine, please read the following notes for the different tempera-
ture ranges.
Engine cold
If the needle is still in the lower range of the dial, this indicates that
the engine has not yet reached operating temperature. Avoid high
engine speeds, full acceleration and heavy engine loads.
Normal temperature
In normal operation the needle will settle somewhere in the centre
of the dial once the engine has reached operating temperature. The
needle may also go further up when the engine is working hard at
high outside temperatures. This is no cause for concern provided
the warning symbol
 in the display does not start flashing.
A1
11
A2
12
A3
15
A4
SET
12
A5
21
13
14
A6
14
A7A8
14
A1
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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 system31
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data For example, in the event of an oil pressure malfunction the oil pres-
sure symbol

will appear in the display. In addition, the following
message will appear:
Switch off engine and check oil level
The message will disappear from the display after about 5 seconds.
If required, the message can be called up again by briefly pressing
the button ⇒page 30, fig. 24.
Driver messages and yellow symbols
If a yellow warning symbol appears in the display, it will automati-
cally be accompanied by the corresponding driver message.
For example, if the symbol
 appears (windscreen washer fluid
low), the display will also show the message:
Please top up washer fluid
The message will disappear after a few seconds. If required, the
message can be called up again by briefly pressing the
button.
Red symbols
A red symbol warns of a serious malfunction.–Stop the vehicle.– Switch off the engine.
– Check the function displayed. Obtain professional assist-
ance if necessary.
The red symbols indicate a Priority 1 fault (serious malfunction).
Should a Priority 1 fault occur, a red warning symbol will appear at
the top of the display ⇒fig. 25. The symbol is accompanied by a
driver message giving you more information about the fault. This
symbol is accompanied by three warning chimes. The symbol will
keep flashing until the fault is corrected.
If several Priority 1 faults are detected at the same time, the symbols
are displayed one after the other for about 2 seconds at a time.
This message will disappear after about 5 seconds, but you can call
it up again at any time by pressing the button ⇒page 30.
SET
SET
Fig. 25 Display:
Symbol for serious
malfunction

Alternator fault
⇒page 32

Fault in brake system/parking
brake
⇒page 32

Coolant level too low / coolant
temperature too high
⇒page 33

Engine oil pressure too low
⇒page 33

Add engine oil immediately
⇒page 34

Fault in the steering system
⇒page 34

Ignition lock defective
⇒page 34

Tyre pressure monitoring
⇒page 39
SET
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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 cooling101
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with diesel engineSupplementary heater– Set the Supplementary heater to auto or off.Models with a diesel engine are equipped with a supplementary
heater to help warm up the interior more quickly. At outside temper-
atures below about +5 °C the supplementary heater is switched on
(and off) automatically when the engine is running, depending on
the coolant temperature, the temperature in the vehicle interior and
the temperature the heater is set to.Deluxe automatic air conditioner plusApplies to vehicles: with deluxe automatic air conditioner plusDescription
The air conditioner is designed to keep the passenger
compartment at the temperature you find most comfort-
able at all times of the year.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 103.
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 combined particle filter and activated charcoal
filter) serves as a barrier against impurities in the outside air,
including dust and pollen, and against unpleasant smells. 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
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Heating and cooling103
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
•
The grille on the control console ⇒page 102, fig. 112 must be
kept free. Please ensure that it is not covered by stickers or similar.
Measuring sensors are located behind it.
Applies to vehicles: with deluxe automatic air conditioner plusSwitching on and off Switching on air conditioner
– Press the button briefly, or
– Press the button.
Switching off air conditioner
– Press the button for at least 2 seconds to switch off
the air conditioner and cut off the supply of fresh air from
outside the vehicle. The display will show “OFF”.The air conditioner will switch on again if you operate the tempera-
ture control.
Note
You can press the button when the ignition is switched off to
activate the "residual heat" function. The system will then heat the
interior using the remaining heat in the engine coolant.Applies to vehicles: with deluxe automatic air conditioner plusAutomatic 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
Button(s)
Function
Page
Switching on and off
⇒page 103
Automatic mode - drivers
side/
front passengers side
⇒page 103
Temperature con-
trol 1
a)
Temperature con-
trol 2a)
a)The rotary control is also used to adjust the blower speed, air distribution
and seat heating.
Temperature selection -
drivers side
Temperature selection -
front passengers side
⇒page 104
Blower - driver's side/
front passenger's side
⇒page 104
b)
b)The symbol differs slightly on some models.
Air recirculation mode
⇒page 105

Air distribution - drivers
side/
front passengers side
⇒page 106
Defrosting windows
⇒page 106
Heated rear window
⇒page 106
Switching air cooling
on/off
⇒page 107
/
Seat heating / seat ventila-
tion
⇒page 114
OFFAUTOAC

OFFAUTOOFF
OFF
AUTO
AUTO
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Heating and cooling 110The synchronisation is cancelled as soon as any adjustments are
made on the front passenger's side.Applies to vehicles: with diesel engineSupplementary heater– Set the Supplementary heater to auto or off.Models with a diesel engine are equipped with a supplementary
heater to help warm up the interior more quickly. At outside temper-
atures below about +5 °C the supplementary heater is switched on
(and off) automatically when the engine is running, depending on
the coolant temperature, the temperature in the vehicle interior and
the temperature the heater is set to.Auxiliary heating and auxiliary
ventilationApplies to vehicles: with auxiliary heating - under development at the time of printingDescription
The auxiliary heating and ventilation systems heat and
cool the interior independently of the engine.The auxiliary heating
 works in conjunction with the air condi-
tioner system, but does not rely on heat from the engine. Instead of
this, the system burns fuel. The system's main function is to warm
up the interior of the vehicle and to defrost the windows in cold
weather.
The auxiliary heating system can be used both when the vehicle is
stationary and when driving (to provide extra heat while the engine
is warming up).The auxiliary ventilation
 also operates independently of the
engine. This feature can be used to cool the interior with the blower
when the vehicle is left parked in the sun.
The system will automatically activate either the auxiliary heating or
the auxiliary ventilation mode, depending on the actual tempera-
ture measured inside the car and the temperature you have set with
the air conditioner controls. It is possible to alter the temperature
setting while the auxiliary heating/ventilation is running.
Switching on and off
There are two different ways of switching on the auxiliary
heating/ventilation system.
•
Immediate start: You can switch the auxiliary heating/ventilation
on and off at any time via the sound system or MMI ⇒page 111. You
can also switch the system on and off using the remote control
⇒page 113.
•
Switching on via timer: You can programme various start times
using the timers ⇒page 111. However you must first activate the
timer before the auxiliary heating/ventilation system will switch on
automatically.
The auxiliary heating/ventilation will switch itself off at the end of
the programmed running time. The running time can be set to 15,
30, 45 or 60 minutes ⇒page 112.
WARNING
•
The auxiliary heating must not be allowed to run when the
vehicle is in a confined space because it can give off toxic fumes.
•
To avoid any possible fire risk, never have the auxiliary heating
switched on when refuelling the vehicle.
•
Because of the high temperatures which occur when the auxil-
iary heating is running, make sure when parking the car that the
exhaust outlet under the car is not obstructed in any way and that
the exhaust gases do not come into contact with flammable mate-
rials (fire risk).
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