2008 AUDI A4 instrument cluster

Airbag system201
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Airbag systemDescription of airbag systemGeneral notes on airbag system
The airbag is an integral part of the car's passive safety
system.In conjunction with the three-point seat belts, the airbag system
gives the front occupants additional protection for the head and
chest in the event of a severe frontal collision.
In a severe side collision the side airbags and the head-protection
airbags reduce the risk of injury to the occupants in the areas of the
body facing the impact ⇒.
In addition to their normal function of protecting the occupants in a
collision, the seat belts also hold them in a position where the
airbags can inflate properly and provide maximum protection.
The airbag system will only work with the ignition on. The airbag
system is monitored electronically; the airbag warning lamp indi-
cates whether the system is functioning properly.
The main parts of the airbag system are:•
the electronic monitoring system (control unit and sensors),
•
the two front airbags,
•
the front side airbags, the side airbags on the outer rear seats*
and the head-protection airbags,
•
the airbag warning lamp in the instrument cluster.
There is a fault in the airbag system if the warning
lamp
•
does not come on when the ignition is switched on,
•
does not go out about 4 seconds after the ignition is switched
on,
•
goes out and then comes on again after the ignition is switched
on,
•
comes on or flickers while the car is moving.
WARNING
•
The airbags are not a substitute for the seat belts; they are an
integral part of the car's overall passive safety system. The airbags
can only offer effective protection if the occupants are wearing
their seat belts. For this reason it is very important to wear the
seat belts at all times ⇒page 194, “Why is it so important to use
seat belts?”.
•
The seat belts and airbags can only provide maximum protec-
tion if the occupants are seated correctly ⇒page 73, “Seats and
storage”.
•
If you do not wear a seat belt, if you lean forward, or are not
seated correctly while the vehicle is in motion, you are at greater
risk of injury should the airbag system be triggered in an accident.
•
Components of the airbag system are located in various parts
of the vehicle. If repairs to other vehicle components make it
necessary to perform work on the airbag system or to remove or
install parts of the airbag system, this may cause damage to the
airbag system. As a result, the airbags may not inflate correctly or
may not be triggered at all in an accident situation. For this reason,
you should always have the work carried out by a qualified work-
shop.
•
If a fault should occur in the airbag system, have the system
checked immediately by a qualified workshop. Otherwise the
system may fail to trigger in an accident.
•
Do not attempt to modify components of the airbag system in
any way.
•
Never make any alterations to the front bumper or the body.
document_0900452a81b1b9de.book Seite 201 Donnerstag, 26. Juli 2007 9:16 09

Airbag system209
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
The key-operated switch for deactivating the front
passenger's airbag is located in the glove box ⇒fig. 222.
– To deactivate the front passenger's airbag, insert the
ignition key into the switch and turn it to position .
– The front passenger's airbag can be reactivated by
turning the key to position .Deactivating front passenger's airbag when a child
safety seat is in use
If you have no alternative but to install a rearward-facing child safety
seat on the front passenger's seat you must deactivate the front
passenger's airbag beforehand.
We recommend, however, that child seats should be only fitted on
the rear seat so that the front passenger's airbag can remain func-
tional and provide protection in an accident ⇒page 210.
Monitoring of airbag system
The airbag warning lamp will light up for a few seconds every time
the ignition is switched on.
If the front passenger's airbag has been deactivated via the key-
operated switch, the indicator lamp “PASSENGER AIRBAG OFF” will
light up constantly as a reminder ⇒page 209, fig. 223. Please refer
also to the description of the
 warning lamp in the instrument
cluster ⇒page 17.When the front passenger's airbag is deactivated using the key-
operated switch, the seat belt warning lamp for the front passenger
 ⇒page 18 is also switched off.
WARNING
•
If you have no alternative but to install a rearward-facing child
seat on the front passenger's seat, the front passenger's airbag
must be deactivated beforehand. Potentially fatal injuries to the
child can result if the front passenger's airbag is not deactivated!
⇒page 211, “Using a child safety seat on the front passenger's
seat”
•
If you have deactivated the front passenger's airbag, reactivate
it as soon as the child seat is no longer needed so that the airbag
can continue to give the required protection.
•
It is the driver's responsibility to ensure that the key-operated
switch is set to the correct position.Note
All the other airbags in the car will remain functional if the front
passenger's airbag has been deactivated with the key-operated
switch.
Fig. 223 Lamp indi-
cates that front
passenger's airbag has
been deactivated via
key-operated switch
AOFF
AON
document_0900452a81b1b9de.book Seite 209 Donnerstag, 26. Juli 2007 9:16 09

Intelligent technology 222Intelligent technologyElectronic stabilisation program (ESP)DescriptionESP increases the car's stability. It reduces the tendency to skid and
improves the stability and roadholding of the vehicle. ESP detects
critical handling situations, such as understeer, oversteer and
wheelspin on the driven wheels. It stabilises the vehicle by braking
individual wheels or by reducing the engine torque. The warning
lamp
 in the instrument cluster starts flashing as soon as the ESP
intervenes.
The ESP incorporates the functions of the anti-lock brake system
(ABS), the traction control system (ASR), the electronic differential
lock (EDL) and the dynamic steering*.
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up under braking until the
vehicle has reached a virtual standstill. You can continue to steer the
vehicle even when the brakes are on full. Keep your foot on the brake
pedal and do not pump the brakes. You will feel the brake pedal
pulsate while the anti-lock brake system is working.
Brake assist system
The brake assist system can speed up the braking process and
shorten the braking distance. It automatically boosts the braking
force if you press the brake pedal quickly in an emergency. On vehi-
cles with adaptive cruise control*, the brake assist system will build
up a small amount of pressure in the hydraulic brake system if it
senses that you are too close to the vehicle in front.
Traction control system (ASR)
In the event of wheelspin, the traction control system reduces the
engine torque to match the amount of grip available. This helps the
car to start moving, accelerate or climb a gradient.Electronic differential lock (EDL)
When the EDL detects wheelspin, it brakes the spinning wheel and
directs the power to the other driven wheel (or wheels on quattro*
versions). This function is active up to about 100 km/h.
To prevent the disc brake of the braked wheel from overheating, the
EDL cuts out automatically if subjected to excessive loads. The
vehicle can still be driven. The EDL will switch on again automati-
cally when the brake has cooled down.
Dynamic steering*
On vehicles with dynamic steering*, the ESP can also intervene in
the steering to stabilise the vehicle in critical situations.
WARNING
•
The grip provided by the ESP, ABS, ASR, EDL and dynamic
steering* systems is still subject to the physical limits of adhesion.
Always bear this in mind, especially on wet or slippery roads. If
you notice the systems cutting in, you should reduce your speed
immediately to suit the road and traffic conditions. Do not let the
extra safety provided tempt you into taking any risks when driving
– this can cause accidents.
•
Please remember that the accident risk always increases if you
drive fast, especially in corners or on a slippery road, or if you
follow too close behind the vehicle in front of you. Please bear in
mind that even ESP, ABS, brake assist, EDL, ASR and dynamic
steering* cannot compensate for the increased accident risk.
•
When accelerating on a uniformly slippery surface (for instance
all four wheels on ice or snow), press the accelerator gradually and
carefully. The driven wheels may otherwise start to spin (in spite
of the integrated control systems), which would impair the car's
stability and could lead to an accident.
document_0900452a81b1b9de.book Seite 222 Donnerstag, 26. Juli 2007 9:16 09

Intelligent technology227
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data 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.
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 228, “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.
document_0900452a81b1b9de.book Seite 227 Donnerstag, 26. Juli 2007 9:16 09

Intelligent technology 228With 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.
Driver message in the instrument cluster displayIf battery power drops to a level at which you may encounter prob-
lems when starting the engine, the following message will appear
in the instrument cluster display:
 Low battery charge: Battery will be charged while driving
This message reminds you that the starting reliability may be
impaired. The message will disappear as soon as you set off and the
battery is charged.
Message comes on and goes out again
If the message appears in the display after the ignition is switched
on or while driving, and goes out again after a period of time, the
battery has been charged up again sufficiently while the vehicle was
being driven.
Message comes on and does not go out
If the message appears in the display after the ignition is switched
on or while driving, and does not go out again, the battery is not
being maintained at the proper power level. Starting reliability may
be impaired. You should have the battery checked by a qualified
workshop as soon as possible.
document_0900452a81b1b9de.book Seite 228 Donnerstag, 26. Juli 2007 9:16 09

Towing a trailer233
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data additional mirrors fitted. Both exterior mirrors should be mounted
on hinged extension brackets. Adjust the mirrors to give sufficient
vision to the rear.
Headlights
Before starting a journey, check the headlight beam settings with
the trailer hitched up. If necessary, alter the height of the headlight
beams by means of the headlight range control ⇒page 60.
Power supply
When you remove the ignition key the power supply to the trailer is
interrupted.
Removable ball joint coupling
Vehicles with a factory-fitted towing bracket are equipped with a
removable ball joint coupling. It is carried under the floor panel on
the left-hand side of the luggage compartment and is secured by a
strap.
Note
We recommend having the car serviced between the normal inspec-
tion intervals if it used frequently for towing a trailer.Applies to vehicles: with towing bracketTrailer stabilisation system
Trailer stabilisation helps to reduce the risk of the vehicle
skidding when towing a trailer.The trailer stabilisation system is operational only when the ESP is
switched on and there is no malfunction in the ESP ⇒page 17.
When is the trailer stabilisation system activated?
Trailer stabilisation is active when the following requirements are
met:•
The ESP must NOT be switched off ⇒page 222,
•
The trailer connector must be properly secured in the vehicle
socket.
•
Vehicle speed must be higher than approx. 60 km/h.
How trailer stabilisation works:
In many cases, the driver can stabilise a swaying trailer by manually
braking the vehicle.
However, if the ESP detects that the trailer is swaying and this is
affecting the towing vehicle, it will automatically brake the vehicle
to stabilise the trailer by slowing it down. The warning lamp
 will
light up in the instrument cluster. If possible, do not turn the
steering wheel at this stage.
In order to warn traffic behind you, the brake lights will come on
during this automatic braking operation.
A trailer weighing less than 70% of the kerb weight of the towing
vehicle may sway quite considerably without the trailer stabilisation
system intervening. This can happen when the swaying movements
of the light-weight trailer are not or hardly passed on to the towing
vehicle and are therefore not detected by the ESP.
If the system for activating the trailer brake lights is defective, this
will be indicated in the instrument cluster display ⇒page 37, “Bulb
monitor ”.
Requirements for correct functioning of the trailer
stabilisation system
If these conditions are not met in full, the trailer stabilisation system
will only intervene to a limited extent or not at all ⇒.
•
The electrical connection between the towing vehicle and the
trailer must be functioning correctly, without any defects.
•
The load on the trailer must be properly secured.
•
The tyre pressures on both the vehicle and the trailer must be
adapted to the load that is being carried.
•
Where possible, operate the trailer with the maximum permitted
draw bar weight.
document_0900452a81b1b9de.book Seite 233 Donnerstag, 26. Juli 2007 9:16 09

Towing a trailer 234•
The trailer overrun brake must be set correctly. This is important
to ensure that the trailer can be braked correctly, to avoid the vehicle
and trailer “jack-knifing” and to prevent excess braking of the trailer.
•
At low outside temperatures, both the towing vehicle and the
trailer should be fitted with winter tyres.
WARNING
It is essential that you adjust your speed to suit the weather, road
and traffic conditions. Do not let the trailer stabilisation system
tempt you into taking any risks when driving – this can cause acci-
dents.•
The ESP and trailer stabilisation system cannot defy the laws
of physics. This should be kept in mind, particularly on slippery
and wet roads and when towing a trailer with a light load.
•
The trailer stabilisation system is functional, regardless of
whether the trailer has a mechanical overrun brake or not.
•
The trailer stabilisation system is not always able to detect
swaying of trailers with a light load and will therefore not inter-
vene.
•
A trailer can still “jack-knife” on slippery roads with little grip,
even if the towing vehicle is equipped with the trailer stabilisation
system.
•
Trailers with a high centre of gravity may even tip over before
they start to sway sideways.
•
If you are not towing a trailer, but the trailer socket is being
used (e.g. for an illuminated bicycle rack), the trailer stabilisation
system may be activated in extreme driving conditions.
•
Please note the additional information and warnings
⇒page 234.
Notes on towing
Driving with a trailer always requires extra care.Weight distribution
Try to avoid towing a loaded trailer with an unladen vehicle. If this
cannot be avoided, drive extra slowly to allow for the unbalanced
weight distribution.
Speed
The stability of the car and trailer is reduced with increasing speed.
For this reason it is advisable not to drive at the maximum permis-
sible top speed in unfavourable road, weather or wind conditions.
This applies especially on a downhill gradient.
You should always reduce speed immediately if the trailer shows
the slightest sign of swaying. Never try to stop the swaying by accel-
erating further.
Always brake in good time. If the trailer has an overrun brake, apply
the brakes gently at first and then firmly. This will prevent the jerking
that can be caused by the trailer wheels locking. Change down in
good time before going down a steep hill so that you can use the
engine braking effect to slow down the vehicle.
Swaying and pitching can be reduced by stabiliser aids. We recom-
mend having stabiliser aids installed when towing trailers with a
high trailer weight. They can be purchased and installed at an Audi
dealer.
Overheating
When climbing long hills in hot weather with the engine running
fast in low gear, you should keep an eye on the coolant temperature
gauge ⇒page 11. Reduce speed immediately if the needle moves to
the top end of the scale. If the temperature warning lamp
 in the
instrument cluster should start flashing, stop the car and let the
engine cool down by running it at idling speed for a few minutes.
document_0900452a81b1b9de.book Seite 234 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids257
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data The positions of the engine oil filler cap and the engine oil dipstick
⇒page 256, fig. 252 (items and ) may be different on some
engine versions.
Engine oilGeneral notesWe recommend that you have the oil change carried out by an Audi
dealership / qualified workshop according to the intervals stated in
the Service Schedule or according to the service interval display in
the instrument cluster.
Whether your vehicle is serviced at flexible service intervals or fixed
service intervals is shown in the Service Schedule.
The correct oil specifications for your engine are listed in the Te c h -
nical data section ⇒page 323, “Performance, weights and dimen-
sions”.
Check that the specifications quoted (VW standards) appear on the
container either singly or in combination with other specifications.
Flexible service intervals (Audi LongLife Service*)
Special engine oils ⇒page 323, “Performance, weights and dimen-
sions” have been developed as part of the Audi LongLife Service
(⇒“Service Schedule”).
This type of oil must be used if you intend to take advantage of the
extended maintenance intervals allowed by the Audi LongLife
Service.•
Do not mix the LongLife oil with oil intended for fixed service
intervals, as the requirements for the extended service intervals are
then no longer guaranteed.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the specified LongLife oil, you
can put in a small quantity of oil for fixed service intervals -
⇒page 323, “Performance, weights and dimensions”. This should not be done more than once and no more than 0.5 litres should be
used.
Fixed service intervals (Inspection Service)*
If you do not take advantage of the LongLife service for your car, you
can use the oils for fixed service intervals - ⇒page 323, “Perform-
ance, weights and dimensions”. In this case, your car must be serv-
iced after a fixed interval of 1 year / 15,000 km (9,000 miles) – see
Service Schedule.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the oil specified for your vehicle,
you can put in a small quantity of oil conforming to the specification
ACEA A2 or ACEA A3 (petrol engines) or ACEA B3 or ACEA B4 (diesel
engines). This should not be done more than once and no more than
0.5 litres should be used.
Vehicles with diesel particulate filter*
The Service Schedule states whether your vehicle is fitted with a
diesel particulate filter.
•
Vehicles with diesel particulate filter must only be filled with
engine oil VW 507 00. This oil can be used regardless of whether the
vehicle is serviced at flexible service intervals (Audi LongLife
Service) or fixed service intervals.
•
Avoid mixing this oil with other engine oils.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the oil specified for your vehicle,
you can put in a small quantity of oil conforming to the specification
VW 506 00 / VW 506 01 or VW 505 00 / VW 505 01 or ACEA B3 /
ACEA B4. This should not be done more than once and no more than
0.5 litres should be used.
A3
A4
document_0900452a81b1b9de.book Seite 257 Donnerstag, 26. Juli 2007 9:16 09