2008 AUDI A5 battery

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 202. 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.
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Heating and cooling 102The 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 202. 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
and 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 air conditioning system require specialist knowl-
edge and special tools. For this reason, please contact a qualified
workshop 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.
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Heating and cooling111
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
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 in the MMI Car menu ⇒page 112. You can
also switch the system on and off using the remote control
⇒page 114.
•
Switching on via timer: You can programme various start times
using the timers ⇒page 112. 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 113.
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).Note
•
It is advisable to open the air outlets when using the auxiliary
heating/ventilation.
•
The auxiliary heating/ventilation will not switch on if the fuel in
the tank has reached the reserve zone.
•
The auxiliary heating/ventilation will not switch on if the battery
charge level is low.
•
The symbols
 (auxiliary ventilation) or
 (auxiliary heating)
flash in the instrument cluster next to the clock display when the
auxiliary heating/ventilation is switched on. Both symbols light
continuously when the timer is activated.
•
At low outside temperatures some visible water vapour may
form in the engine compartment. This is a normal phenomenon,
and no reason for concern.
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Heating and cooling 114Applies to vehicles: with auxiliary heating - under development at the time of printingRemote control
The auxiliary heating and auxiliary ventilation can also be
switched on or off with the remote control.Switching on
– Press the button for about 2 seconds to activate the
auxiliary heating/ventilation ⇒fig. 130.
Switching off
– Press the button for about 2 seconds to switch
off the auxiliary heating/ventilation.Changing the battery
– Push back and remove the battery cover on the remote
control ⇒fig. 131.
– Change the battery. The diagram in the battery compart-
ment shows how the battery should be fitted. The new
battery must be of the same type as the old battery.
– Re-fit the battery cover.
When it is switched on, the auxiliary heating or auxiliary ventilation
starts immediately and remains on for the period set in the menu.
The maximum running time is 60 minutes.
If you want to switch the system on again after the end of the
programmed running time, press the button .
Transmitter indicator lamp
The transmitter indicator lamp will flash accordingly to show
whether the command you sent via the remote control was
successful.
When you switch the system on by pressing the button the
indicator lamp will flash green for about 30 seconds to confirm that
the heating/ ventilation has been switched on. When you switch the
system off by pressing the button the indicator lamp will
flash red to confirm that the heating/ ventilation has been switched
off.
If the remote control is outside the transmitting range the indicator
lamp will flash red slowly. If there is a fault in the system (e.g. fuel
level is down to reserve), the indicator lamp will flash red rapidly. In
both cases the command will not be executed.
When the remote control battery is almost completely flat, the
transmitter indicator lamp will not light up and no commands will
be executed.
Fig. 130 Remote
control for auxiliary
heatingFig. 131 Remote
control: Changing
battery

A1
OFF
A2

A1
A3

A1
OFF
A2
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Automatic gearbox 136Applies to vehicles: with multitronic®Manual release of selector lever
The selector lever can be released manually if the elec-
trical power supply should fail.The manual release mechanism is behind the ashtray.
– Slide open the cover for the ashtray.
–Slide the switch ⇒fig. 150 to the right to release the
ashtray.
– Take out the ashtray .
– You will now see a small cover cap at the front of the
opening in the ashtray mounting unit.– Loosen and remove this cover cap.
– Use a screwdriver or similar object to press down the pin,
which is now accessible, and hold it down ⇒fig. 151.
– Now press the interlock button on the selector lever and
move the selector lever to position N.
The selector lever can only be moved out of position P if the ignition
key is inserted and the ignition is switched on. If the power supply
should ever fail (discharged battery, etc.) and the vehicle has to be
pushed or towed, the selector lever must first be moved to
position N. This is possible after operating the manual release
mechanism.
Fig. 150 Removing
ashtrayFig. 151 Manual
release of selector
lever
AA
AB
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Airbag system177
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The airbag system can only be activated once; if the airbag has
been triggered, the system must be replaced. Should the airbag
system or airbag modules have to be replaced, the qualified work-
shop carrying out the replacement will document all details in the
appropriate section of the Service Schedule.
•
If you sell the vehicle, please remember to pass on the
complete Service Wallet to the new owner. If any of the airbags
have been deactivated, it is important that the new owner is also
given the relevant documents.
•
The relevant safety requirements must be observed when the
vehicle or components of the airbag or belt tensioner systems are
scrapped.
•
In an accident in which one or more airbags are triggered the
alternator and the starter are - for safety reasons - both discon-
nected from the battery via a pyrotechnic circuit breaker.
−Any repairs to the pyrotechnic circuit breaker must always
be performed by a qualified workshop (accident risk).
−The relevant safety requirements must be observed when
the vehicle or the circuit breaker are scrapped.
When are the airbags triggered?
The airbag system is triggered in collisions with a severe
impact.The airbag system is designed so that the airbags for the driver and
front passenger are triggered in a severe frontal collision.
In severe side collisions the side airbags on the impact side of the
vehicle are triggered together with the head-protection airbag.
The front airbags, side airbags and one of the head-protection
airbags may be triggered together in certain types of accident.The airbag system is not triggered in minor frontal or side collisions,
or in rear collisions or if the car overturns. In these situations the
occupants are protected by wearing the seat belts.
Factors determining the triggering response
It is not possible to define the exact triggering response of the
airbag system in all possible situations, since the circumstances in
different types of accident will vary considerably. Important factors
include, for example, the nature (hard or soft) of the object which
the car hits, the angle of impact, vehicle speed and so on.
Whether the airbags are triggered depends primarily on the vehicle
deceleration rate resulting from the collision. By processing the
signals from the sensors located in the vehicle, the electronic
control unit is immediately able to evaluate the severity of the colli-
sion and activate the restraint systems accordingly. If the decelera-
tion rate is below the predefined reference value in the control unit
the airbags will not be triggered, even though the accident may
cause extensive damage to the car.
Note
The airbag releases a fine dust when it inflates. This is quite normal
and does not mean there is a fire in the vehicle.
WARNING (continued)
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Intelligent technology 202Replacing tyres
On vehicles with four-wheel drive, all four tyres must have the same
rolling circumference. Also avoid using tyres with varying tread
depths ⇒page 245, “Replacing wheels and tyres”.
Off-roader?
Your Audi does not have enough ground clearance to be used as an
off-road vehicle. It is therefore best to avoid rough tracks and
uneven terrain as much as possible.
WARNING
•
Even with four-wheel drive, you should always adjust your
speed to suit the conditions. Do not let the extra safety provided
tempt you into taking any risks when driving – this can cause acci-
dents.
•
The braking ability of your car is limited by the grip of the tyres.
In this respect, your car is no different from a car without four-
wheel drive. So do not be tempted to drive too fast on icy or slip-
pery roads just because the car still has good acceleration in these
conditions (accident risk).
•
On wet roads bear in mind that the front wheels may start to
“aquaplane” and lose contact with the road if the car is driven too
fast. If this should happen, there will be no sudden increase in
engine speed to warn the driver, as with a front-wheel drive car. So
do not drive too fast in the wet: adjust your speed to suit the
conditions (accident risk).
Power managementThis system helps to ensure reliable starting
The power management controls the distribution of elec-
trical energy and thus helps to ensure that there is always
enough power available to start the engine.If a vehicle with a conventional electrical system is left parked for a
long time, the battery will gradually lose its charge because certain
electrical equipment (such as the immobiliser) continues to draw
current even when the ignition is off. In some cases there may not
be enough power available to start the engine.
Your vehicle is equipped with an intelligent power management
system to control the distribution of electrical energy. This signifi-
cantly improves reliability when starting the engine, and also
prolongs the life of the battery.
The main functions incorporated in the power management system
are battery diagnosis, residual current management and dynamic
power management.
Battery diagnosis
The battery diagnosis function constantly registers the condition of
the battery. Sensors detect the battery voltage, battery current and
battery temperature. This enables the system to calculate the
current power level and charge condition of the battery.
Residual current management
The residual current management reduces power consumption
while the vehicle is parked. It controls the supply of power to the
various electrical components while the ignition is switched off. The
system takes the battery diagnosis data into consideration.
Depending on the power level of the battery, the individual electrical
components are switched off one after the other to prevent the
battery from losing too much charge and to ensure that the engine
can be started reliably.
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Intelligent technology203
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data Dynamic power management
While the vehicle is moving, this function distributes the available
power to the various electrical components and systems according
to their requirements. The power management ensures that on-
board systems do not consume more electrical power than the
alternator can supply, and thus maintains the maximum possible
battery power level.
Note
•
The power management system is not able to overcome the
given physical limits. Please remember that the power and life of
the battery are limited.
•
A warning message will appear ⇒page 204, “Driver message in
the instrument cluster display” if the battery power has dropped to
a level where reliable starting is impaired.
Points to remember
Starting ability has first priority.Short trips, city traffic and low temperatures all place a heavy load
on the battery. In these conditions a large amount of power is
consumed, but only a small amount is supplied. The situation is also
critical if electrical equipment is in use when the engine is not
running. In this case power is consumed when none is being gener-
ated.
In these situations you will be aware that the power management
system is intervening to control the distribution of electrical power.
When the vehicle is parked for long periods
If you do not drive your vehicle for a period of several days or weeks,
the power management will gradually shut off the on-board
systems one by one, or reduce the amount of current they are using.
This limits the amount of power consumed and helps to ensure reli-
able starting even after a long period.Please note that certain convenience features, such as the Audi
advanced key*, the remote control key or the electrical seat adjust-
ment may not be available when you unlock the vehicle. These func-
tions will be restored when you switch on the ignition and start the
engine.
With the engine switched off
If you listen to the radio or use the other MMI functions when the
engine is not running, this will discharge the battery.
The MMI display will show this warning message before the battery
power drops to a level where the starting ability is impaired.
Please start engine, otherwise system will switch off
in 3 minutes.
This message warns you that the system you are using will be
switched off automatically after 3 minutes. You should therefore
start the engine if you wish to continue using the system.
When the engine is running
Although the alternator generates electrical power, the battery can
still become discharged while the vehicle is being driven. This can
occur when a lot of power is being consumed but only a small
amount supplied, especially if the battery is not fully charged
initially.
To restore the necessary energy balance, the system will then
temporarily shut off the electrical components that are using a lot
of power, or reduce the current they are consuming. Heating
systems in particular use a large amount of electrical power. If you
notice, for instance, that the seat heating* or the rear window
heater is not working, they may have been temporarily switched off
or regulated to a lower heat output. These systems will be available
again as soon as sufficient electrical power is available.
You may also notice that the engine runs at a slightly faster idling
speed. This is quite normal, and no cause for concern. The increased
idling speed allows the alternator to meet the greater power
requirement and charge the battery at the same time.
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