check engine light AUDI S4 2008 User Guide

Driver information system
38Applies to vehicles: with battery power warning systemBattery power

If battery power drops to a level at which you may encounter prob-
lems when starting the engine, th e display will show the symbol

and the driver message Low battery charge: Battery will be charged
while driving .
Please bear in mind that the star ting ability of the engine may be
impaired while this message is shown.
Message comes on and goes out again
If the message appears in the displ ay 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 displ ay 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.
Engine oil level (without dipstick)

 Add oil, max. 1L. You may continue driving.
If the  symbol lights up in conjunction with this driver message,
add not more than 1 litre of oil at the next opportunity
⇒ page 259 .
Check engine oil level (with dipstick)

 Please check oil level If the
 symbol lights up in conjunction with this driver message,
please check the engine oil level as soon as possible ⇒page 258 .
Top up the oil at the next opportunity ⇒page 259 .
Engine oil sensor defective


Oil level ! Sensor defective
If the 
symbol lights up, take the vehicle to a qualified workshop
and have the oil level sensor checked. Until then it is advisable to
check the oil level every time you fill up with fuel ⇒page 258 .
Applies to vehicles: with diesel engine and diesel particulate filterDiesel particulate filter obstructed


Particle filter. See Owner's Manual
When the symbol

lights up you can assist the self-cleaning func-
tion of the filter by driving accordingly. You should drive at a speed
of at least 60 km/h (engine speed about 2,000 rpm) for about
15 minutes in 4th or 5th gear, or with the selector lever in position S
on vehicles with automatic gearbox*. As a result of the increase in
temperature the soot in the filter will be burned off. The symbol will
disappear once the cleaning proce ss has been completed success-
fully.
If the symbol

does not go out, please contact a qualified work-
shop and have the fault rectified.
For further information on the diesel particulate filter ⇒page 229 .
WARNING
It is essential that you adjust your speed to suit the weather, road,
terrain and traffic co nditions. The recommended driving speed
must never lead to the driver disregarding the traffic regulations.
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Seats and storage89
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with 230 Volt Euro socketOn-board 230 Volt Euro socketElectrical equipment can be connected to the 230 Volt
Euro socket in the rear centre console.The 230 Volt Euro socket can only be used when the ignition
is on ⇒ .
– Fold up the lid to access the socket.
– Plug the Euro connector into the socket. This will auto- matically release the child safety device.LED in electrical socket
Appliances suitable for connection
Electrical equipment with a Euro plug connector can be connected
to the 230 Volt Euro socket. The appliances connected to the
230 Volt Euro socket must not exceed a power rating of 150 W
(300 W peak power). If you connect more than one applia
nce, the total power rating of all
appliances must not exceed 150 W. If necessary, check the type
plates on the connected appliances for details of the power ratings.
Connected appliances must be in perfect condition and free of
defects.
WARNING
•
Heavy appliances or plugs (such as power supply units) can
damage the mounting of the 230 Volt Euro socket if they are
suspended directly from the socket – Risk of injury!
•
Make sure that all connected appliances are securely stowed
when driving to prevent them from being catapulted through the
car under braking or in an accident – Danger to life!
•
Never spill liquid over the socket – Danger to life! If the socket
does get wet, ensure that it is absolutely dry before using it again.
•
Improper use of the electrical socket or appliances connected
to it can cause injuries or fire – Risk of injury!
•
Never leave children unattended in the vehicle while the engine
is running – Risk of injury!
•
Connected appliances behave differ ently than when they are
connected to the public electricity grid. As a result, the connected
appliances may become hot during operation – Risk of injury!
•
When using adapters or extens ion cables, please remember
that the child safety device on the 230 Volt Euro socket is deacti-
vated and the socket is live – Risk of injury!
•
Do not insert c onductive materials, su ch as knitting needles,
into the contacts of the 230 Volt Euro socket – Danger to life!
•
Switch off the connected electrical appliances if the inverter
trips out due to overheat ing – Risk of injury!Caution
•
Please observe the operating instructions for the connected
appliances.
Steady green light:
The socket is ready for use.
Flashing red light:
The socket has tripped out due
to a power surge, overheating or
similar
Fig. 100 Rear centre
console: 230 Volt Euro
socket
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Intelligent technology
228With the engine switched off
If you listen to the radio or us e the other MMI functions when the
engine is not running, this will discharge the battery.
The MMI display will show this warn ing 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 am ount 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 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 ra pidly 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 in flated 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 comp artment 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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Checking and topping up fluids
254Checking and topping up fluidsBonnetReleasing the bonnet
The bonnet is released from inside the vehicle.– Open the driver's door.
– Pull the lever under the dash board in the direction indi-
cated (arrow) ⇒fig. 250.The bonnet springs out of its lock.
Opening the bonnetBefore opening the bonnet make sure that the windscreen
wiper arms are not lifted away from the glass. Otherwise the
paint may get damaged.
– Lift the bonnet slightly ⇒.
– Press the release catch under the bonnet upwards ⇒fig. 251. This will release the arrester hook.
– Open the bonnet.The bonnet is held open by two gas-filled struts.
WARNING
To avoid the risk of being scalded, never open the bonnet if you see
steam or coolant escaping from the engine compartment. Wait
until no steam or coolant can be seen before opening the bonnet.
Fig. 250 Detail of foot-
well on driver's side:
Release lever
Fig. 251 Release catch
under the bonnet
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Checking and topping up fluids261
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The coolant additive G12++ can be mixed only with additives
G12+ and G12.
Checking coolant level
The coolant level can be checked at a glance.– Switch off the ignition.
– Read off coolant level on radiator expansion tank ⇒fig. 257. When the engine is cold it should be between
the “MIN” and “MAX” marks. When the engine is hot it
may be slightly above the “MAX” mark.The coolant level should be checke d with the engine switched off.
The coolant level is monitored by a warning lamp in the instrument
cluster ⇒page 33 . However, we recommend that it should be
checked occasionally.
Coolant losses
Any loss of coolant normally indicates a leak in the cooling system.
In this case the cooling system should be inspected by a qualified
workshop without delay. It is not sufficient merely to top up the
coolant. If there are
no leaks in the system, a loss of coolant can only occur
if the coolant boils and is forced out of the system as a result of
overheating.
Caution
Radiator sealants must not be added to the coolant. Such additives
could seriously impair the function of the cooling system.Topping up the coolant
Be careful when topping up coolant.– Switch off the engine.
– Wait for the engine to cool down.
– Cover the cap on the expansion tank ⇒fig. 257 with a
cloth, and carefully unscrew the cap anti-clockwise
⇒ .
– Add coolant.
– Screw the cap on again tightly.Make sure that the coolant meets the required specifications
⇒page 260, “Coolant”. Do not use a different type of additive if anti-
freeze additive G12++, G12+ or G12 is not available. In this case use
only water and bring the coolant concentration back up to the
correct level as soon as possible by putting in the specified additive.
Always top up with fresh, unused coolant.
Do not fill above the “MAX” mark. Ex cess coolant is forced out of the
system through the valve in the filler cap when the engine gets hot.
If a lot of coolant has been lost, wait for the engine to cool down
before putting in cold coolant. Failure to do so could result in
serious engine damage.
Fig. 257 Engine
compartment: Mark-
ings on radiator expan-
sion tank
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Checking and topping up fluids
262
WARNING
•
The cooling system is under pr essure. Do not unscrew the cap
on the expansion tank when the engine is hot: you could be
scalded by escaping steam
•
The coolant and coolan t additive can be a health hazard. Store
the coolant additive in the original container in a safe place out of
reach of children – risk of poisoning.For the sake of the environment
Drained off coolant should not be used again. Drain off the used
coolant into a suitable container and dispose of it in the proper
manner (observe environmental regulations).Radiator fan
The radiator fan can start running spontaneously.The radiator fan is driven by the engine via a poly V-belt. The speed
of the fan is varied by a viscous clutch according to the temperature.
There is also an auxiliary electric fan, which cuts in automatically
whenever the temperature of the coolant and the engine compart-
ment rises above a certain level.
The auxiliary fan can continue to run for as long as 10 minutes after
stopping the engine – even after the ignition is switched off. It may
also start running suddenly ⇒ after a while if•
residual heat raises the coolant temperature, or
•
the hot engine compartment is ad ditionally heated up by the
sun.
WARNING
When working in the engine compa rtment be aware that the radi-
ator fan may start running suddenly – risk of injury.
Brake fluidChecking brake fluid level
The brake fluid level can be checked at a glance.– Check the fluid level on the brake fluid reservoir ⇒fig. 258. It should always be between the “MIN” and
“MAX” marks.In right-hand drive vehi cles the brake fluid reservoir is on the other
side of the engine compartment.
The fluid level may drop slightly after a period of time due to the
automatic compensation for brake pad wear. This is quite normal.
However, if the level goes down noticeably in a short time, or drops
below the “MIN” mark, there may be a leak in the brake system. If
the fluid level in the reservoir is too low, this will be indicated by the
brake warning lamp ⇒page 32 . If this should happen, take the car
to a qualified workshop immediately and have the brake system
inspected.
Fig. 258 Engine
compartment: Mark-
ings on brake fluid
reservoir
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Checking and topping up fluids
264Please note that certain convenience features, such as the Audi
advanced key*, the remote control ke y or the electrical seat adjust-
ment may not be available when you unlock the vehicle. These func-
tions will be restored when you swit ch 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 s pecialist 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 unde r 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 corrosi ve. Wear protective gloves and
safety glasses. Do not tilt the ba ttery - acid can leak out of the
vapour vent. If electrolyte should splash into the eyes rinse at once
for several minutes using clear wa ter. 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, cons ult 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.
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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 re sulting high-energy sparks can
cause injury.
•
A highly explosive mixture of gases is given off when the
battery is under charge. Only char ge 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. Re move the ignition key. The minus
cable of the battery must be disc onnected. 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 th e battery from the vehicle's electrical
system, first disconnect the minu s cable and then the plus cable.
•
Before reconnecting the battery, turn off all electrical equip-
ment. First connect the plus cabl e, 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 th e 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 equi pment. 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
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Checking and topping up fluids267
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Windscreen washerPlain water on its own is not sufficient for the windscreen
washer system.The container for the windscreen washer
 contains the cleaning
fluid for the windscreen and the headlight washer system*
⇒ fig. 260. Container capacity: ⇒page 321 .
Plain water on its own is not enough to clean the glass properly. It
is therefore advisable to add a suitable washer fluid additive (with
wax solvent) to the water. A washer fluid with freeze-resistant addi-
tive should be used in winter.
Caution
•
Never put in radiator anti-freeze or other additives.
•
Never use washer fluid which contains paint thinners or solvents
as it can damage the paintwork.
Fig. 260 Engine
compartment: Wind-
screen washer
container
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