2008 AUDI A4 engine

Intelligent technology223
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
•
To ensure that the ASR works properly, all four wheels must be
fitted with identical tyres. Any differences in the rolling radius of the
tyres can cause the system to reduce engine power when this is not
desired.
•
Should a malfunction occur in the ABS or EDL, both the ABS
warning lamp
 and the ESP warning lamp
 ⇒page 19 will light
up.
•
In the event of a malfunction in the ESP system, the warning
lamp  ⇒page 17 will light up.
•
If a malfunction should occur in the ABS, the ESP, EDL and ASR
will also be out of action.
•
The systems can make noises when they intervene.
Switching on and off
The ESP is switched on automatically when the engine is
started.
Switching off the traction control system (ASR)
In particular circumstances, it may be advisable to switch off the
traction control system (ASR) to allow a certain amount of wheel
slip. For example:•
Rocking the car backwards and forwards to free it
•
Driving in deep snow or on loose surfaces
•
Driving with snow chains
Press the button briefly ⇒fig. 232 or ⇒fig. 233. The
warning lamp
 will light up and the message ASR off will appear
in the driver information system display.
The traction control system (ASR) can only be switched off at speeds
below 50 km/h on vehicles with front-wheel drive. At 70 km/h it will
switch on again automatically. The ASR can be deactivated at any
speed on vehicles with four-wheel drive.
Switching off the ESP
Press the button for longer than 3 seconds. The ESP
warning lamp  will light up and the message ESP switched off will
appear in the display. The ASR is also deactivated when the ESP is
switched off.
Switching on
Press the button again. The message ESP/ASR on will
appear briefly on the display.
Fig. 232 Version A:
Centre console
(bottom), ESP OFF
button
Fig. 233 Version B:
Centre console (top),
ESP OFF button
ESP OFFESP OFFESP OFF
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Intelligent technology 224
WARNING
You should switch off the ESP only if your driving ability and traffic
conditions allow you to do so safely. Please note that, when the
ASR and ESP are switched off, the driven wheels may start to spin,
causing the vehicle to lose grip, in particular on slippery or wet
roads - danger of skidding!
Note
The ASR and ESP cannot be switched off when the adaptive cruise
control (ACC)* is on.BrakesNew brake pads
New brake pads do not give full braking effect for the first 400 km,
they must first be “bedded in”. However, you can compensate for
the slightly reduced braking effect by applying more pressure on
the brake pedal. Avoid placing a heavy load on the brakes during the
running-in period.
We ar
The rate of wear on the brake pads depends a great deal on how you
drive and the conditions in which the vehicle is operated. Negative
factors are, for instance, city traffic, frequent short trips or hard
driving with abrupt starts and stops.
Wet roads; road salt
When you are driving at a speed higher than 80 km/h and have the
windscreen wipers switched on the brake pads are very briefly
brought into contact with the brake discs. This automatic process
which goes unnoticed by the driver is carried out at regular intervals
and is intended to improve braking response in wet conditions.In certain conditions, such as in heavy rain, or after washing the car
or driving through water, the full braking effect can be delayed by
moisture (or in winter by ice) on the discs and brake pads. The
brakes should be “dried” by pressing the pedal to restore full
braking effect.
The effectiveness of the brakes can also be temporarily reduced if
the car is driven for some distance without using the brakes when
there is a lot of salt on the road in winter. The layer of salt that accu-
mulates on the discs and pads can be removed with a few cautious
brake applications.
Corrosion
There may be a tendency for dirt to build up on the brake pads and
corrosion to form on the discs if the car is used infrequently, or if
you only drive low mileages without using the brakes very much.
If the brakes are not used frequently, or if corrosion has formed on
the discs, it is advisable to clean off the pads and discs by braking
firmly a few times from a moderately high speed ⇒.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may
mean that one of the two brake circuits has failed. Drive immedi-
ately to the nearest qualified workshop and have the fault rectified.
On the way to the dealer, be prepared to use more pressure on the
brake pedal and allow for longer stopping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is
too low. The brake fluid level is monitored electronically.
Brake servo
The brake servo amplifies the pressure you apply to the brake pedal.
It only works when the engine is running.
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Intelligent technology225
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
WARNING
•
When applying the brakes to clean off deposits on the pads and
discs, select a clear, dry road. Be sure not to inconvenience or
endanger other road users; do not risk an accident.
•
Never let the car coast with the engine switched off (this can
cause accidents).Caution
•
Never let the brakes “drag” by leaving your foot on the pedal
when you do not really intend to brake. This overheats the brakes,
resulting in longer stopping distances and greater wear.
•
Before driving down a long, steep gradient, it is advisable to
reduce speed and move the selector lever to a lower gear. In this
way you will make use of the engine braking effect and relieve the
load on the brakes. If you still have to use the brakes, it is better to
brake firmly at intervals than to apply the brakes continuously.Note
•
If the brake servo is out of action due to a malfunction, or if the
car has to be towed, you will have to press the brake pedal consid-
erably harder to make up for the lack of servo assistance.
•
If you wish to equip the car with accessories such as a front
spoiler or wheel covers, it is important that the flow of air to the
front wheels is not obstructed, otherwise the brakes can overheat.
Power steering (servotronic)The power steering assists the driver when turning the
steering wheel (with the engine running).The power steering assists the driver by reducing the force needed
to turn the steering wheel. The degree of power assistance is
adapted electronically, depending on the speed.If a fault should occur in the servotronic system the power steering
will still operate. The degree of power assistance will, however, no
longer adapt to different speeds. If the electronic regulating system
is not working properly, this is most noticeable when turning the
steering wheel at low speeds (for instance when parking) – more
effort will be required than usual. The fault should be corrected by
a qualified workshop as soon as possible.
The power steering does not function when the engine is switched
off. In this case the steering wheel is very hard to turn.
If the steering is held at its turning limit when the car is stationary,
this will place an excessive load on the power steering system. In
this case, the power steering system will make noises. It will also
reduce the idling speed of the engine.
Caution
Do not keep the steering in the full-lock position for longer than
15 seconds when the engine is running – this could cause damage
to the power steering system.
Note
•
If the power steering should fail at any time or the engine is
switched off (for instance when being towed), the car can still be
steered. However, more effort will be required to turn the steering
wheel.
•
If the system is leaking or malfunctioning, please take the car to
a qualified workshop as soon as possible.
•
The power steering requires a special hydraulic fluid. The fluid
reservoir is located at the front of the engine compartment on the
left ⇒page 256. The correct fluid level in the reservoir is important
for the power steering to function properly. The hydraulic fluid level
is checked at the Inspection Service.
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Intelligent technology 226Applies to vehicles: with four-wheel driveFour-wheel drive (quattro
®)
On quattro models the engine power is distributed to all
four wheelsGeneral notes
On four-wheel drive vehicles, the engine power is distributed to all
four wheels. The distribution of power is controlled automatically
according to your driving style and the road conditions. Also refer
to ⇒page 222, “Description”.
The four-wheel drive is specially designed to complement the supe-
rior engine power of your Audi. This combination gives the car
exceptional handling and performance capabilities – both on
normal roads and in more difficult conditions, such as snow and ice.
Even so (or perhaps especially for this reason), it is important to
observe certain safety points ⇒.
Winter tyres
Thanks to its four-wheel drive, your car will have plenty of traction
in winter conditions, even with the standard tyres. Nevertheless, we
still recommend that winter tyres or all-season tyres should be fitted
on all four wheels when winter road conditions are expected, mainly
because this will give a better braking response.
Snow chains
On roads where snow chains are mandatory, this also applies to cars
with four-wheel drive ⇒page 273, “Snow chains”.
Replacing 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 270, “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
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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.
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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.
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Your vehicle and the environment229
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Your vehicle and the environmentRunning inA new vehicle should be run in over a distance of 1,500 km. For the
first 1,000 km the engine speed should not exceed 2/3 of the
maximum permissible engine speed – do not use full throttle and do
not tow a trailer or caravan. From 1,000 to 1,500 km you can gradu-
ally increase the engine rpm and road speed.
During its first few hours of running, the internal friction in the
engine is greater than later on when all the moving parts have
bedded down.
How the vehicle is driven for the first 1,500 km also influences the
engine quality. After the first 1,500 km you should continue driving
at moderate engine speeds, in particular when the engine is cold.
This helps to reduce wear and tear on the engine and increases the
potential mileage which can be covered by the engine.
You should also avoid driving with the engine speed too low.
Change down to a lower gear when the engine no longer runs
“smoothly”. Excessively high engine speeds are prevented by an
automatic rev limiter.Emission control systemsCatalytic converter
Applies to vehicles with petrol engine: The vehicle must only be
used with unleaded petrol, otherwise the catalytic converter will be
destroyed.
Never run the tank completely dry. The irregular fuel supply can
cause misfiring, which would allow unburnt fuel to enter the
exhaust system, which could cause overheating and damage the
catalytic converter.Diesel particulate filter
Applies to vehicles with diesel engine: The diesel particulate filter
can filter out almost all soot particles contained in the exhaust gas.
In normal driving conditions the filter is self-cleaning. Should the
self-cleaning function of the filter not be able to operate, e.g. when
the vehicle is continuously used only for short trips, the filter
becomes obstructed with soot and the symbol

for the diesel
particulate filter lights up ⇒page 38.
WARNING
•
Because of the high temperatures which can occur in the emis-
sion control system (catalytic converter or diesel particulate
filter), do not park the vehicle where the exhaust can come into
contact with flammable materials under the car (e.g. on grass or
at the forest edge). - Fire hazard!
•
Do not apply any underseal agents in the area around the
exhaust system - fire hazard!
How to improve economy and minimise pollutionFuel economy, environmental impact and wear on the engine,
brakes and tyres depend largely on the way you drive the vehicle. By
adopting an economical driving style and anticipating the traffic
situation ahead, you can reduce fuel consumption by 10-15%. The
following section gives you some tips on lessening the impact on
the environment and reducing your operating costs at the same
time.
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Your vehicle and the environment 230Anticipate well in advance
A car uses most fuel when accelerating. If you anticipate hazards
and speed changes well in advance, you will need to brake less and
thus accelerate less. Wherever possible, let the car slow down grad-
ually with a gear engaged, for instance when you can see that the
next traffic lights are red. This takes advantage of the engine
braking effect, reducing wear on the brakes and tyres. Emissions
and fuel consumption will drop to zero due to the overrun fuel cut-
off.
Change gear early to save fuel
An effective way of saving fuel is to change up quickly through the
gears. Running the engine at high rpm in the lower gears uses an
unnecessary amount of fuel.
Manual gearbox: Shift up to second gear as soon as possible. If
possible, we recommend shifting up to the next gear at approx.
2,000 rpm.
Automatic gearbox: Press the accelerator slowly and avoid using
the “kick-down” feature.
Avoid driving at high speed
Avoid travelling at top speed. Fuel consumption, exhaust emissions
and noise levels all increase very rapidly at higher speeds. Driving at
moderate speeds will help to save fuel.
Do not let the engine idle for longer than necessary
It is worthwhile switching off the engine when waiting in a traffic
jam, at level crossings or at traffic lights with a long red phase. The
fuel saved after only 30 - 40 seconds is greater than the amount of
fuel needed to restart the engine.
The engine takes a very long time to warm up when it is running at
idling speed. Mechanical wear and pollutant emissions are also
especially high during this initial warm-up phase. It is therefore best
to drive off immediately after starting the engine. Avoid running the
engine at high speed.Regular servicing
Regular servicing can establish a basis for good fuel economy
before you start driving. A well-serviced engine gives you the
benefit of improved fuel efficiency as well as maximum reliability
and an enhanced resale value. A badly tuned engine can consume
up to ten percent more fuel than necessary.
Avoid short trips
The engine and emission control system need to reach their proper
working temperature in order to minimise fuel consumption and
emissions.
A cold engine uses disproportionately more fuel. The engine only
reaches its working temperature after about four kilometres, when
fuel consumption will return to a normal level. This is the reason
why we recommend avoiding short trips wherever possible.
Maintain the correct tyre pressures
Always make sure the tyres are inflated to the correct pressures
⇒page 268 to save fuel. If the tyre pressures are just 0.5 bar too low,
this can increase the fuel consumption by as much as 5 %. Due to
the greater rolling resistance, under-inflation also increases tyre
wear and impairs handling.
Do not use winter tyres all through the year; they will increase fuel
consumption by up to 10 %.
Avoid carrying unnecessary loads
Every kilo of extra weight will increase the fuel consumption, so it is
worth checking the luggage compartment occasionally to make
sure that no unnecessary loads are being transported.
A roof carrier is often left in place for the sake of convenience, even
when it is no longer needed. At a speed of 100-120 km/h your car will
use about 12 % more fuel as a result of the extra wind resistance
caused by the roof carrier - even when it is empty.
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