2008 AUDI A4 check engine light

Driver information system 32Alternator fault

If the symbol
 flashes in the instrument cluster display, there is an
alternator fault or a fault in the vehicle's electrical system. In addi-
tion, a message will appear. This message will disappear after about
5 seconds, but you can call it up again at any time by pressing the
button.
You should normally be able to drive to the next available qualified
workshop. However, you should avoid using electrical equipment
that is not absolutely necessary because this will drain the battery.
Caution
If the coolant warning lamp
 in the instrument display lights up
as well as the alternator warning lamp while driving ⇒page 33, stop
the vehicle immediately and switch off the engine. In this case the
coolant pump is no longer being driven, and there is a risk of engine
damage.
Fault in the brake system

A fault in the brake system should be corrected as soon as
possible.If the symbol

flashes in the display, there is a fault in the
brake system. The symbol is accompanied by a driver
message giving you more information about the fault. This
message will disappear after about 5 seconds, but you can
call it up again at any time by pressing the button:
Stop vehicle and check brake fluid level
– Stop the vehicle.
– Check the brake fluid level ⇒page 262.
– Obtain professional assistance if necessary.Warning! Fault in ABS brake system. Contact
workshop
– Drive carefully to the nearest qualified workshop and
have the fault rectified ⇒.
Parking brake ! Please contact workshop
– If the symbol appears after you switch on the ignition
when the vehicle is stationary, please check whether you
can release the parking brake. If this is possible, you
should drive without delay to the nearest qualified work-
shop and have the fault rectified. If the parking brake
cannot be released you should obtain professional
assistance.
– If this symbol should appear while driving, there may be
a malfunction in the drive-away assist or the emergency
brake functions. You may not be able to apply the parking
brake. It is also possible that you cannot release the
parking brake after it has been applied. Drive the vehicle
to a qualified workshop and have the fault repaired.
If the ABS fails, the ABS warning lamp
 will light up together with
the brake warning symbol
 ⇒.
WARNING
•
Before opening the bonnet and checking the brake fluid level,
observe the warning information on ⇒page 255, “Working on
components in the engine compartment”.
•
If the brake fluid level in the reservoir is too low, this could
result in an accident. Do not drive on. You should obtain profes-
sional assistance.
•
If the brake warning lamp lights up together with the ABS
warning lamp, this can mean that the control function of the ABS
is out of action. As a result the rear wheels can lock relatively
SET
SET
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Driver information system33
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data easily when braking. This could cause the tail of the vehicle to skid
sideways. Drive carefully to the nearest qualified workshop and
have the fault rectified.
Note
The warning lamp
 in the instrument cluster will start flashing as
well if there is a fault in the brake system.
Fault in the cooling system

Faults in the cooling system must be rectified immedi-
ately.If the
 symbol flashes in the display, this means that
either the coolant temperature is too high or the coolant
level is too low. The symbol is accompanied by a driver
message giving you more information about the fault. This
message will disappear after about 5 seconds, but you can
call it up again at any time by pressing the button:
Switch off engine, check coolant level
–Stop the vehicle.
– Switch off the engine.
– Check the coolant level ⇒page 261.
– Add more coolant if necessary ⇒page 261.
– Wait for the symbol to go out before driving on.
– Obtain professional assistance if necessary.
If the coolant level is correct, the overheating may be caused by a
malfunction of the radiator fan.If the alternator warning lamp lights up as well ⇒page 32, it is
possible that the drive belt has broken.
WARNING
•
If your vehicle should break down for technical reasons, stop it
at a safe distance away from moving traffic, switch off the engine
and turn on the hazard warning lights ⇒page 61, “Hazard
warning lights ”.
•
Never open the bonnet if you can see or hear steam or coolant
escaping from the engine compartment; there is a risk of being
scalded. Wait until you can no longer see or hear escaping steam
or coolant.
•
The engine compartment of any motor vehicle is a dangerous
place. Before carrying out any work in the engine compartment,
switch off the engine and allow it to cool down. Please observe the
important safety warnings ⇒page 255, “Working on components
in the engine compartment”.Caution
Do not drive on if the symbol
 has come on to indicate a fault in
the cooling system, otherwise there is a risk of damaging the
engine.
Engine oil pressure too low

If the engine oil pressure is too low the fault must be recti-
fied immediately.If the

symbol flashes in the display, the oil pressure is
too low. The symbol is accompanied by a driver message
giving you more information about the fault. This message
WARNING (continued)
SET
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Driver information system 34
will disappear after about 5 seconds, but you can call it up
again at any time by pressing the button:
Switch off engine and check oil level
– Stop the vehicle.
– Switch off the engine.
– Check the engine oil level ⇒page 258.
– Obtain professional assistance if necessary.If the engine oil level is too low
If the engine oil level is too low, add more oil ⇒page 259.
If the engine oil level is correct
If the

symbol flashes and the engine oil level is correct, obtain
professional assistance. Do not drive on. Do not continue to run the
engine, not even at idle speed.
Note
The oil pressure warning lamp

is not an indicator for the oil
level. The oil level should therefore be checked regularly.
Add engine oil immediately

 WARNING! Please add oil immediately
If the  symbol lights up, you must add oil immediately
⇒page 259.
Fault in the steering system

The steering wheel cannot be unlocked if there is a fault
in the electronic steering lock.If the symbol

flashes in the display, there is a malfunc-
tion in the electronic steering lock. The symbol is accompa-
nied by a driver message giving you more information
about the fault. This message will disappear after about
5 seconds, but you can call it up again at any time by
pressing the button:
Do not drive vehicle. Steering defective
– You should obtain professional assistance.
–Do not have the vehicle towed away.
WARNING
The vehicle must not be towed if there is a fault in the electronic
steering lock: the steering will be locked and the vehicle cannot be
steered. Towing a vehicle with locked steering can cause an acci-
dent.
Note
On some models the symbol may look slightly different.Ignition lock defective

A fault in the ignition lock must be rectified immediately.If the symbol

flashes in the display, there is a malfunc-
tion in the electronic ignition lock. The symbol is accompa-
nied by a driver message giving you more information
about the fault. This message will disappear after about
SET
SET
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Driver information system35
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
5 seconds, but you can call it up again at any time by
pressing the button:
Ignition lock defective. Contact workshop!
–Do not switch off the engine.
– Drive the vehicle without delay to a qualified workshop
and have the fault repaired.The ignition cannot be switched off if there is a fault in the elec-
tronic ignition lock. For this reason, you should drive the vehicle
without delay to a qualified workshop and have the cause of the
fault repaired.
If the vehicle is equipped with the advanced key* feature, you
should not switch off the engine with the Stop/Start button because
it cannot be started again after the ignition has been switched off.
Note
On some models the symbol may look slightly different.Yellow symbols
A yellow symbol indicates a malfunction or other item
requiring attention.
Yellow symbols indicate a Priority 2 fault.
Yellow symbols are accompanied by one warning chime. The
symbol is accompanied by a driver message giving you more infor-
mation about the fault. This message will disappear after about
5 seconds, but you can call it up again at any time by pressing the
button.
The function indicated should be checked as soon as possible. The
yellow symbol will only go out when the fault has been rectified.
If several Priority 2 faults are detected at the same time, the symbols
are displayed one after the other for about 2 seconds at a time.
SET
Fig. 26 Display: Yellow
warning symbol

Dynamic steering
⇒page 36 and
⇒page 159

Brake pads worn
⇒page 37

Battery power*
⇒page 38

Bulb monitor*
Bulb failure*
⇒page 37

Check engine oil level
⇒page 38 or
⇒page 38

Engine oil sensor defective
⇒page 38

Fuel level low
⇒page 37

Washer fluid level low*
⇒page 37

advanced key*
Key not in vehicle
⇒page 36

Light sensor/rain sensor defec-
tive
⇒page 37

Diesel particulate filter*
obstructed
⇒page 38
SET
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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, the display will show the symbol

and the driver message Low battery charge: Battery will be charged
while driving.
Please bear in mind that the starting 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 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.
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 levelIf 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 process 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 conditions. 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 appliance, 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 differently 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 extension 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 conductive materials, such 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 overheating – 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 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 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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