key AUDI A4 2008 B8 / 4.G Workshop Manual

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

Child safety211
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
If children lean forward or are otherwise out of position when
the car is moving, they are at greater risk of injury in an accident.
This is particularly the case if the child is travelling on the front
passenger's seat and the airbag system is triggered in an accident.
There is then a risk of serious or potentially fatal injury.
•
To ensure proper protection, it is important to wear the seat
belts in the correct position ⇒page 197, “How to wear seat belts
properly”. Always check that the belt is properly positioned
according to the instructions provided by the manufacturer of the
child safety seat. Incorrectly worn seat belts can give rise to inju-
ries even in a minor collision.
•
Never install a rearward-facing child safety seat on the front
passenger's seat if the front passenger's airbag has not been deac-
tivated ⇒page 211.
•
Extra caution is advised if you are installing a child safety seat
using the same mounting bolts as the existing car seat belts. The
bolts must be screwed in all the way to the full depth of the
mounting holes and tightened to a torque of 50 Nm. Failure to
observe this precaution could result in potentially fatal injury. We
recommend having the installation performed by a qualified
workshop.
Using a child safety seat on the front passenger's seat
Whenever possible, child safety seats should always be
installed on the rear seat.For safety reasons, we recommend that child safety seats should be
installed on the rear seats whenever possible. However, if you have
to use a child seat on the front passenger's seat when there is no
other alternative, it is most important to note the following warn-
ings:
WARNING
•
Do not use a rearward-facing child safety seat on the front
passenger's seat unless the front passenger's airbag has been
deactivated. The child seat would be directly in the path of the
airbag as it inflates, and the child could sustain serious or fatal
injuries if the airbag were to be deployed.
•
However, if you have no alternative but to use a rearward-
facing child seat on the front passenger's seat, the front
passenger's airbag must be deactivated beforehand by means of
the key-operated switch* ⇒page 208. Failure to observe this
precaution could result in serious or potentially fatal injury.
•
Make sure that the front passenger's airbag is reactivated by
means of the key-operated switch* as soon as the child seat is no
longer needed on the front passenger's seat.
•
When using a child safety seat of the type which faces in the
direction of travel, the front passenger's seat must be moved back
to the rearmost position.
WARNING (continued)
document_0900452a81b1b9de.book Seite 211 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

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 trailer237
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
– Also check the shaft section of the ball joint and its asso-
ciated mechanical parts to make sure they are clean and
undamaged.Continued ⇒page 237, “Fitting the ball joint (step 2)”.
WARNING
It is important to keep the mounting fixture clean. Otherwise the
ball joint may fail to engage securely (accident risk).Applies to vehicles: with removable towing bracketFitting the ball joint (step 2)The spring mechanism inside the ball joint must
be in the "ready" position.
– Check that the red marking ⇒fig. 238 on the knob is
inside the green zone on the ball joint.
– Check that the locking ball is inside the hole in the
shaft section of the ball joint.
– Check that the knob protrudes visibly from the ball joint,
so that there is a clear gap between the knob and the
ball joint.
The ball joint can only be installed if the internal spring mechanism
is in the ready position.
Continued ⇒page 237, “Fitting the ball joint (step 3)”.Applies to vehicles: with removable towing bracketFitting the ball joint (step 3)Setting the spring mechanism to the "ready"
position (if required)
– Insert the key ⇒fig. 239 for locking the ball joint into
the lock on the knob and turn it clockwise.
Fig. 238 Removable
towing bracket: Ball
joint
A2A1A3
Fig. 239 Removable
towing bracket:
Setting the spring
mechanism to the
"ready" positionFig. 240 Removable
towing bracket:
Inserting the ball joint
A4
document_0900452a81b1b9de.book Seite 237 Donnerstag, 26. Juli 2007 9:16 09

Towing a trailer 238
– Pull out the knob in direction , hold and turn in direc-
tion until the locking ball engages ⇒.
Inserting the ball joint
– With the spring mechanism in the “ready” position,
insert the ball joint into the mounting fixture and push it
upwards ⇒page 237, fig. 240 in the direction indicated
(arrow) ⇒. The spring mechanism should then
engage automatically with an audible click.
– Lock the ball joint by turning the key anti-clockwise.
– Take out the key and press the cover cap provided onto
the lock.Continued ⇒page 238, “Fitting the ball joint (step 4)”.
WARNING
•
If it is not possible to set the spring mechanism to the "ready"
position as described above, do not use the ball joint. Please take
your vehicle to a qualified workshop.
•
To avoid injury, keep your hands away from the knob and the
cover piece when inserting the ball joint into the mounting fixture.Note
Make sure that the knob can turn freely when the ball joint is
inserted.
Applies to vehicles: with removable towing bracketFitting the ball joint (step 4)Safety check
– Check that the green marking ⇒fig. 241 on the knob
is inside the green zone on the ball joint.
– Check that the knob is directly against the ball joint, so
that there is no gap between the knob and the ball
joint.
– Check that the ball joint is locked and the key is removed
(so that the knob cannot be pulled out).
Aa
Ab
A5
Fig. 241 Removable
towing bracket: Safety
checkFig. 242 Area below
rear bumper: Electrical
socket for trailer
A6
A7
document_0900452a81b1b9de.book Seite 238 Donnerstag, 26. Juli 2007 9:16 09

Towing a trailer239
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
– Check that the ball joint fits tightly in the mounting
fixture (try moving it about to check).
Electrical socket for trailer
– The cable of the towing bracket can be connected to the
socket ⇒page 238, fig. 242.If the safety check is not satisfactory, the ball joint must be fitted
again properly.
WARNING
To avoid accidents, the ball joint must meet all the safety require-
ments listed in the safety check. The towing bracket must not be
used if any one of these requirements is not met. If this is the case,
you should contact a qualified workshop.Applies to vehicles: with removable towing bracketRemoving the ball joint
– Take off the cover cap and insert the key ⇒fig. 243 in
the lock on the knob.
– Unlock the ball joint by turning the key clockwise.
– Take hold of the ball joint and pull out the knob in direc-
tion .
– Keep hold of the knob and turn it as far as it will go in
direction .
– Release the knob. The spring mechanism will remain in
the "ready" position ⇒.
– Pull the ball joint down out of the mounting fixture.
– Then swivel the socket up ⇒fig. 244 as far as it will go.
The mounting fixture will be closed automatically.
– Put away the ball joint attachment under the floor panel
in the luggage compartment.
WARNING
Make sure that the socket unit has closed off the mounting fixture
of the towing bracket properly. Otherwise the ball joint may fail to
engage securely if dirt accumulates in the mounting fixture.
Fig. 243 Removable
towing bracket:
Removing the ball joint
Fig. 244 Area below
rear bumper: Folding
up the socketA8
Aa
Ab
document_0900452a81b1b9de.book Seite 239 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids255
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Working on components in the engine compartment
Extra caution is necessary when working on components
in the engine compartment.Always be aware of the danger of injury and scalding as well as the
risk of accident or fire when working in the engine compartment
(e.g. when checking and refilling fluids). Always observe the warn-
ings listed below and follow all normal safety precautions. The
engine compartment of any motor vehicle is a potentially
hazardous area. ⇒.
WARNING
•
Switch off the engine.
•
Remove the ignition key.
•
Apply the parking brake.
•
Put the gear lever in neutral or selector in P.
•
Wait for the engine to cool down.
•
Keep children away from engine compartment.
•
Never spill fluids on hot engine components. These fluids can
cause a fire (e.g. radiator anti-freeze).
•
Take care not to cause short circuits in the electrical system,
especially when working on the battery.
•
Do not touch the radiator fan when the engine is hot. The fan
may start running suddenly.
•
Do not unscrew the cap on the expansion tank when the engine
is hot. The cooling system is under pressure.
•
Protect face, hands and arms by covering the cap with a large,
thick rag to protect against escaping coolant and steam.
•
If any tests have to be performed with the engine running,
there is an extra safety risk from the rotating parts, such as the
drive belts, alternator and radiator fan, etc., and from the high-
voltage ignition system.
•
Vehicles with automatic gearbox: Never open the throttle inad-
vertently (for instance by hand from the engine compartment) if a
gear is engaged while the vehicle is stationary with the engine
running. The vehicle could otherwise start moving immediately
and possibly cause an accident.
•
Observe the following additional warnings if work on the fuel
system or the electrical system is necessary:
−Always disconnect the battery.
−Do not smoke.
−Never work near naked flames.
−Always keep an approved fire extinguisher immediately
available.Caution
When topping up fluids make sure the correct fluid is put into the
correct filler opening. This can otherwise cause serious malfunc-
tions or engine damage.
For the sake of the environment
Inspect the ground underneath your vehicle regularly so that any
leaks are detected at an early stage. If you find oil spots or other
fluids, have your vehicle inspected by a qualified workshop.
Note
On right-hand drive vehicles* some of the containers / reservoirs
mentioned below are located on the other side of the engine
compartment.
WARNING (continued)
document_0900452a81b1b9de.book Seite 255 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids 264Please 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.
Winter conditions
At low temperatures the battery has to work very hard. It also
provides only a fraction of the starting power it has at normal
temperatures.
For this reason, we recommend having the battery checked and
charged if necessary before the start of winter ⇒page 265.
WARNING
•
All work on batteries requires specialist knowledge. For queries
regarding the vehicle battery please contact an Audi dealership or
other qualified workshop (risk of chemical burns / risk of explo-
sion).
•
The battery must not be opened. Do not attempt to make any
changes to the electrolyte level of the battery. Otherwise, there is
a risk that a mixture of oxygen and hydrogen gas can accumulate
and cause an explosion.Note
If the vehicle is to be left standing for a period of several weeks at
extremely low temperatures, the battery should be removed from
the vehicle. This ensures that it cannot “freeze up” and be
damaged.
Important safety warnings for handling a car battery
All work on batteries requires specialist knowledge.The vehicle battery is located under the floor panel in the luggage
compartment.
WARNING
Always be aware of the danger of injury and chemical burns as
well as the risk of accident or fire when working on the battery and
the electrical system.•
Wear safety glasses. Do not allow acid or lead particles to come
into contact with eyes, skin or clothing.
•
Battery acid is extremely corrosive. Wear protective gloves and
safety glasses. Do not tilt the battery - acid can leak out of the
vapour vent. If electrolyte should splash into the eyes rinse at once
for several minutes using clear water. Then seek medical care
immediately. Neutralize any acid splashes on the skin or clothing
with soap solution, and rinse off with plenty of water. If acid is
swallowed by mistake, consult a doctor immediately.
•
Keep open flames, sparks, uncovered lights and lit cigarettes
away from battery. Avoid sparks (including those from static

Wear safety glasses!

Battery acid is extremely corrosive. Wear protec-
tive gloves and safety glasses.

Keep open flames, sparks, uncovered lights and
lit cigarettes away from battery!

A highly explosive mixture of gases is given off
when the battery is under charge!

Keep children away from the battery and battery
acid.
document_0900452a81b1b9de.book Seite 264 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids265
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data charges) when handling cables and electrical equipment. Never
cross the battery poles. The resulting high-energy sparks can
cause injury.
•
A highly explosive mixture of gases is given off when the
battery is under charge. Only charge battery in a well ventilated
area.
•
Keep children away from the battery and battery acid.
•
Switch off all electrical equipment before starting any work on
the vehicle electrical system. Remove the ignition key. The minus
cable of the battery must be disconnected. When changing a light
bulb, it is sufficient to only turn off the light.
•
Before disconnecting the battery, turn off the anti-theft
system! Otherwise, the alarm will sound.
•
When disconnecting the battery from the vehicle's electrical
system, first disconnect the minus cable and then the plus cable.
•
Before reconnecting the battery, turn off all electrical equip-
ment. First connect the plus cable, then the minus cable. The
battery cables must not be connected to the wrong battery poles
- serious risk of cable fire.
•
Never charge a frozen or thawed out battery - risk of explosion
and chemical burns! A battery must be replaced once it has been
frozen. When it is discharged the battery can freeze at tempera-
tures around 0°C.
•
Make sure that the vapour hose is always attached to the
battery.
•
Never use a damaged battery - risk of explosion! Replace a
damaged battery immediately.Caution
•
Never disconnect the car's battery with the engine running or
with the ignition turned on, otherwise the electrical system or elec-
trical components will be damaged.
•
Do not expose the battery to direct sunlight over a long period of
time, as the intense ultraviolet radiation can affect the battery
housing.
•
If the car is left standing for long periods, protect the battery
from extreme cold temperature so that it does not “freeze up” and
become damaged.
Charging the battery
Terminals for charging the battery are fitted in the engine
compartment.– Note the warnings ⇒ in “Important safety warnings
for handling a car battery” on page 264 and ⇒.
– Switch off all electrical equipment. Remove the ignition
key.
– Open the bonnet ⇒page 254.
– Open the red cap on the positive terminal ⇒fig. 259.
– Follow the correct procedure for connecting the charger
cables to the jump-start terminals (terminal with red cap
= “positive”, terminal with hexagon = “negative”).
WARNING (continued)
Fig. 259 Engine
compartment: Termi-
nals for jump leads and
battery charger
document_0900452a81b1b9de.book Seite 265 Donnerstag, 26. Juli 2007 9:16 09