2008 AUDI A4 check engine light

Contents 2ContentsNotes on this Owner's
Manual
. . . . . . . . . . . . . . . . . . . . . .
Controls
. . . . . . . . . . . . . . . . . . . . .
Controls and displays
. . . . . . . . . .
Overview . . . . . . . . . . . . . . . . . . . . . .
Instruments and
warning/indicator lamps
. . . . . . .
Instruments . . . . . . . . . . . . . . . . . . . .
Fuel gauge . . . . . . . . . . . . . . . . . . . . .
Warning and indicator lamps . . . . .
Driver information system
. . . . . .
Introduction . . . . . . . . . . . . . . . . . . . .
On-board computer . . . . . . . . . . . . .
Speed warning function . . . . . . . . .
Auto-check control . . . . . . . . . . . . . .
Tyre pressure monitoring system .
Doors and windows
. . . . . . . . . . . .
Central locking system . . . . . . . . . .
Boot lid . . . . . . . . . . . . . . . . . . . . . . . .
Child-proof catches . . . . . . . . . . . . .
Electric windows . . . . . . . . . . . . . . .
Sun roof . . . . . . . . . . . . . . . . . . . . . . .
Lights and vision
. . . . . . . . . . . . . . .
Lights . . . . . . . . . . . . . . . . . . . . . . . . .
Interior lights . . . . . . . . . . . . . . . . . . .Clear vision . . . . . . . . . . . . . . . . . . . .
Windscreen wipers . . . . . . . . . . . . .
Rear-view mirrors . . . . . . . . . . . . . .
Digital compass . . . . . . . . . . . . . . . .
Seats and storage
. . . . . . . . . . . . .
Manual adjustment of front seats
Electric adjustment of front seats
Seat memory . . . . . . . . . . . . . . . . . .
Head restraints . . . . . . . . . . . . . . . .
Front armrest . . . . . . . . . . . . . . . . . .
Luggage compartment . . . . . . . . .
Roof carrier . . . . . . . . . . . . . . . . . . . .
Roof load . . . . . . . . . . . . . . . . . . . . .
Cup holders . . . . . . . . . . . . . . . . . . .
Ashtrays . . . . . . . . . . . . . . . . . . . . . .
Cigarette lighter and electrical
sockets . . . . . . . . . . . . . . . . . . . . . . .
On-board 230 Volt Euro socket . . .
Storage compartments . . . . . . . . .
Heating and cooling
. . . . . . . . . . .
Deluxe automatic air conditioner .
Deluxe automatic air conditioner -
basic settings . . . . . . . . . . . . . . . . . .
Deluxe automatic air conditioner
plus . . . . . . . . . . . . . . . . . . . . . . . . . .
Deluxe automatic air conditioner
plus - basic settings . . . . . . . . . . . .
Auxiliary heating and auxiliary
ventilation . . . . . . . . . . . . . . . . . . . . .
Seat heating . . . . . . . . . . . . . . . . . . .
Driving
. . . . . . . . . . . . . . . . . . . . . . . . .
Steering . . . . . . . . . . . . . . . . . . . . . . .
Ignition lock . . . . . . . . . . . . . . . . . . .
Starting and stopping the engine
with the advanced key . . . . . . . . . . Electro-mechanical parking brake
Cruise control system . . . . . . . . . . .
adaptive cruise control (ACC)
. .
Speed and distance control system
Driver messages . . . . . . . . . . . . . . .
System limitations . . . . . . . . . . . . . .
Audi braking guard . . . . . . . . . . . . .
Audi lane assist
. . . . . . . . . . . . . . . .
Audi lane assist . . . . . . . . . . . . . . . .
Audi side assist
. . . . . . . . . . . . . . . .
Lane change assist feature . . . . . .
Notes . . . . . . . . . . . . . . . . . . . . . . . . .
Audi drive select
. . . . . . . . . . . . . . .
Adjusting the vehicle set-up . . . . .
Automatic gearbox
. . . . . . . . . . . . .
multitronic®, tiptronic (6-speed
gearbox) . . . . . . . . . . . . . . . . . . . . . . .
Parking aid
. . . . . . . . . . . . . . . . . . . . .
General notes . . . . . . . . . . . . . . . . . .
Audi parking system . . . . . . . . . . . .
Audi parking system plus . . . . . . . .
Audi parking system advanced . . .
Switching display and acoustic
signals on and off . . . . . . . . . . . . . .
Towing bracket . . . . . . . . . . . . . . . . .
Error messages . . . . . . . . . . . . . . . . .
HomeLink
. . . . . . . . . . . . . . . . . . . . . .
Universal transmitter . . . . . . . . . . . . 5
7
9
9
11
11
14
15
21
21
25
28
30
39
42
42
51
53
53
55
57
57
6364
65
68
71
73
73
74
75
77
78
79
83
84
85
86
87
89
90
93
93
100
101
109
110
114
116
116
116
118121
125
128
128
134
140
142
145
145
149
149
156
159
159
162
162
169
169
169
170
171
177
177
178
179
179
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Instruments and warning/indicator lamps 12Warning symbol in instrument cluster

If the symbol
 lights up in the display, this means that either the
coolant temperature is too high or the coolant level is too low
⇒page 33.
If the needle is at the top end of the dial, this means the coolant
temperature is too high. Stop the vehicle, switch off the engine and
wait for it to cool down. If the warning lamp starts flashing again
after just a short distance, contact a qualified workshop.
WARNING
•
Before opening the bonnet and checking the coolant level,
please observe the warning information on ⇒page 255, “Working
on components in the engine compartment”.
•
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.Caution
•
Additional lights and other accessories in front of the air inlet
reduce the cooling effect of the radiator. At high outside tempera-
tures and high engine loads, there is a risk of the engine over-
heating.
•
The front spoiler also ensures proper distribution of the cooling
air when the vehicle is moving. If the spoiler is damaged this can
reduce the cooling effect, which could cause the engine to overheat.
You should obtain professional assistance.
Rev counter
The rev counter indicates the number of engine revolu-
tions per minute.You should select a lower gear if the engine speed drops below
1500 rpm. The start of the red zone on the dial indicates the
maximum engine speed which may be used briefly when the engine
is warm and after it has been run in properly. However, it is advisable
to change up a gear or move the selector lever to “D” (or lift your
foot off the accelerator) before the needle reaches the red zone.
Caution
Never allow the rev counter needle ⇒page 11, fig. 2 to go into
the red zone on the dial for more than a very brief period: there is a
risk of damaging the engine. The start of the red zone on the dial is
different for some engine versions.
For the sake of the environment
Changing up a gear early will help you to save fuel and minimise
engine noise.
button
This button has a number of different functions.
A2
SET
Fig. 3 Instrument
cluster: SET button
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Instruments and warning/indicator lamps 16Additional warning and indicator lamps are displayed on vehicles
equipped with the adaptive cruise control* ⇒page 134.
Note
A number of functions are monitored by the auto-check control
⇒page 21. If a malfunction should occur, this will be shown by the
display in the instrument cluster either with a red symbol (priority 1
– serious malfunction) or a yellow symbol (priority 2 – other
malfunction or item requiring attention).Applies to vehicles: with Audi drive selectDynamic steering

If the warning lamp
 lights up when you switch on the ignition and
goes out when the engine has started, the dynamic steering is acti-
vated.
If the warning lamp  stays on after the engine has started, this
indicates a malfunction in the system. You can continue driving
carefully at reduced speed to the next qualified workshop, however
the steering may feel heavier and its response may be more sensi-
tive than usual. In addition, it is possible that the steering wheel will
be off centre when driving in a straight line.
WARNING
Have the system malfunction in the dynamic steering repaired by
a qualified workshop as soon as possible – risk of accident.
Note
•
If the warning lamp
 flashes, this indicates that the dynamic
steering is being initialised. The message “Dynamic steering: Initial-
ising” ⇒page 36 will appear in the driver information system
display.
•
The stabilisation functions of the dynamic steering ⇒page 222
are not available in the event of a system malfunction.
Applies to vehicles: with petrol engineEngine management

This warning lamp monitors the engine management
system on petrol engines.The
 warning lamp (Electronic Power Control) lights up when the
ignition is switched on to show that the lamp is working properly.Note
If the warning lamp lights up while the vehicle is moving, this indi-
cates a fault in the engine management system. The engine should
be serviced by a qualified workshop without delay.Applies to vehicles: with diesel engineGlow plug system

The indicator lamp lights up to show that the glow plugs
are preheating.Your vehicle is equipped with an automatic glow plug system.
The indicator lamp
 lights up while the glow plugs are preheating.
If the engine fails to start immediately, the glow plugs have not
finished preheating. In this case, keep the clutch pedal depressed
(or keep your foot on the brake if your vehicle has an automatic
gearbox) until the engine starts.

Anti-lock brake system (ABS)
⇒page 19

Electro-mechanical parking
brake/Audi hold assist*
⇒page 20

Fault in brake system
⇒page 20
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Instruments and warning/indicator lamps17
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Note
•
If the glow plug indicator lamp should start flashing while the
vehicle is moving, this indicates a fault in the engine management
system. The engine should be serviced without delay.
•
If the indicator lamp fails to light up when the ignition is
switched on, this can mean that the glow plug system is defective.
The engine should be serviced.
Electronic stabilisation program (ESP)

This warning lamp monitors the electronic stabilisation
program.The warning lamp
 has the following functions:
•
It flashes when the ESP or traction control system (ASR) inter-
venes while the vehicle is in motion.
•
The warning lamp will light up continuously if the ESP or the
traction control system (ASR) has been switched off using the ESP
OFF button ⇒page 222.
•
It lights up when the ignition is switched on and should go out
again after about 2 seconds. This signals that the lamp is working
properly.
•
It will light up continuously if there is a malfunction in the ESP.
•
It will also come on if a fault should occur in the ABS because the
ESP operates in conjunction with the ABS.
If the battery has been disconnected, if the battery voltage is very
low, or if the engine has been started from an outside power source,
the ESP system will perform an initialisation of the various on-board
sensors while you drive the first few metres. The warning lamp will
light up during this period. It will go out when the initialisation has
been completed.
If the warning lamp lights up and stays on after the engine is
started, this may mean that the control system has temporarily
switched off the ESP. In this case the ESP can be reactivated by switching the ignition off and then on again. If the warning lamp
goes out, this means the system is fully functional.
For further information on the ESP ⇒page 222.
Airbag system

This warning lamp monitors the airbag and seat belt
tensioner system.The warning lamp
 should light up for a few seconds when the
ignition is switched on.
If the warning lamp does not go out, or if it lights up, flashes or
flickers when the vehicle is moving, this indicates a malfunction in
the system. This is also the case if the warning lamp does not light
up when the ignition is switched on.
WARNING
If a malfunction should occur, have the system checked immedi-
ately by a qualified workshop. If this is neglected, there is a risk
that the airbag system and/or belt tensioners may not be acti-
vated in an accident.Tyre pressure monitoring

The tyre pressure should be corrected as soon as possible
if it is too low.If the
 symbol flashes for about a minute and then remains lit after
you switch on the ignition, there is a fault in the system. Please
contact the nearest qualified workshop as soon as possible.
For more detailed information on the tyre pressure monitoring
system, please refer to ⇒page 39.
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Instruments and warning/indicator lamps19
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: with cruise control systemCruise control

The indicator lamp
 in the instrument cluster lights up when the
cruise control system is operating.
Anti-lock brake system (ABS)

The warning lamp monitors the ABS and the electronic
differential lock (EDL).The warning lamp
 lights up for a few seconds when the ignition
is switched on and while the engine is being started. The lamp goes
out again once the system has run through an automatic test
sequence.
There is a fault in the ABS if:
•
the warning lamp
 does not light up when the ignition is
switched on,
•
the warning lamp does not go out again after a few seconds,
•
the warning lamp lights up when the vehicle is moving.
The vehicle can still be braked in the normal way (except that the
ABS control function is out of action). Please take the vehicle to a
qualified workshop as soon as possible. For further information on
the ABS ⇒page 222.
If a fault occurs in the ABS, the ESP warning lamp will also light up.
Fault in the main brake system
If the ABS warning lamp
 lights up together with the brake
warning lamp
 ⇒page 32, this indicates a fault in the ABS func-
tion, and possibly a malfunction in the main brake system as well
⇒.
If there is a malfunction in the brake system the symbol
 will light
up in the instrument cluster. Please refer to ⇒page 32.Fault on the electronic differential lock (EDL)
The EDL works in conjunction with the ABS. If a malfunction should
occur in the EDL, this is indicated by the ABS warning lamp
.
Please take the vehicle to a qualified workshop as soon as possible.
For further information on the EDL ⇒page 222.
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 warning lamp
 should light up together with the
ABS warning lamp
, stop the vehicle immediately and check the
brake fluid level in the reservoir. If the fluid level has dropped
below the "MIN" mark you must not drive on - otherwise there may
be an increased accident risk. You should obtain professional
assistance.
•
If the brake fluid level is OK, the fault in the brake system may
have been caused by a failure of the ABS control function. As a
result the rear wheels can lock relatively 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.
Applies to vehicles: with Audi hold assistAudi hold assist

This warning lamp monitors the Audi hold assist function.Audi hold assist helps the driver to keep the vehicle stationary while
the engine is running, for instance on steep gradients, at traffic
lights or in stop-and-go traffic. When the Audi hold assist function
is on, you don't have to keep your foot on the brake to prevent the
vehicle from accidentally rolling away. Once it detects that the
vehicle is stopped, Audi hold assist keeps the vehicle stationary. The
green symbol
 in the instrument cluster indicates that the func-
tion is activated. You can now take your foot off the brake pedal.
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Instruments and warning/indicator lamps 20When the vehicle has been stationary for an extended period, Audi
hold assist will automatically apply the parking brake. In this case,
the green symbol
 will change to red
.
Electro-mechanical parking brake

This warning lamp monitors the electro-mechanical
parking brake.The warning lamp
 lights up when the parking brake is applied
with the ignition on. After the ignition has been switched off the
lamp will stay on for about 30 seconds. The warning lamp will light
up for about 30 seconds if the parking brake is applied with the igni-
tion switched off.
The warning lamp should go out when the parking brake is released.
If the warning lamp flashes continuously after the parking brake has
been applied, the brake may not be strong enough to hold the
vehicle on a slope. This may be due to the brakes overheating.
Please note the following points:
•
If the gradient is too steep to park the vehicle safely, the display
will show the message Caution: Vehicle parked too steep.
•
In the event of a fault in the parking brake system the symbol

will also appear in the instrument cluster display together with the
message Parking brake! You should have the fault corrected by a
qualified workshop without delay.
Brake system

The warning lamp flashes if the brake fluid level is too low
or if there is a fault in the ABS system or the parking
brake.If the warning lamp
 flashes, there is a fault in the brake system.
The symbol
 in the instrument cluster display will flash at the same time. You can press the button to obtain a message
explaining the fault ⇒page 32.
If a failure should occur in the ABS, the ABS warning lamp
 will
light up together with the brake warning lamp
 ⇒.
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 warning lamp does not go out, or if it lights up
when driving, the brake fluid level in the reservoir is too low – this
may cause an increased accident risk. Stop the vehicle and do not
drive on. You should obtain professional 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
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.
SET
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Driver information system 22CD and radio displayIf no priority 1 or 2 faults have been detected by the auto-check
control, the name or frequency of the current radio station and the
selected waveband will appear the upper part of the display.
When a CD is playing, the display will show the current title. If the
vehicle is equipped with a CD changer* the display will also show
the number of the CD being played (CD1 to CD6).Outside temperature display
The outside temperature is shown when the display is
activated.
At temperatures below +5°C a snowflake symbol appears next to the
temperature display. This is to warn the driver to take extra care
when there is a risk of ice on the road.
When the vehicle is stationary or travelling at very low speeds, the
temperature displayed may be slightly higher than the actual
outside temperature as a result of the heat radiated from the
engine.
The temperature units can be set to °F or °C on the sound system or
MMI* system. The outside temperature is automatically displayed in
the units you have selected. Please refer to the sound system or
MMI* Operating Manual for further details.
WARNING
Do not rely on the outside temperature display as an ice warning.
Please bear in mind that there may be patches of ice on the roads
even at outside temperatures around +5°C.Applies to vehicles: with manual gearbox and gear-change indicatorGear-change indicator
This additional indicator function can help to save fuel.
Fig. 9 Display: Radio
informationFig. 10 Display:
Outside temperature
Fig. 11 Display: Gear-
change indicator
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Driver information system 30•
Speed warning - to set the speed above which a warning signal
will sound.
Speed limit warning 2 can be adjusted in increments of 10 km/h
between 30 and 240 km/h.
Auto-check controlIntroductionThe auto-check control checks important components and vehicle
systems. These background checks are run constantly, as long as
the ignition is switched on.
A message is displayed in the instrument cluster if a fault should
occur or if any maintenance or repairs are urgently required. This is
accompanied by an audible warning signal. Depending on the
priority of the fault, a red or yellow warning symbol lights up in the
display.
The red symbols indicate a serious malfunction, whereas the yellow
ones represent other malfunctions or items requiring attention.
Additional messages to assist the driver may be shown with the red
or yellow symbols.
Automatic gearbox* function test
The auto-check control automatically checks the vehicle systems
when the ignition is switched on. If the selector lever is in position
P or N, the following instruction will appear:
When stationary apply footbrake while selecting gear
When a gear (R, D etc.) is selected, this message disappears and the
auto-check control function is displayed.
The driver message will disappear 30 seconds after switching on
the ignition or earlier, if there are other driver messages or malfunc-
tions.If one or more faults are detected, the driver information message
(as above) will disappear about 15 seconds after the engine has
been started and the appropriate fault symbol(s) will appear in the
display. The warning display will be accompanied by the corre-
sponding warning chime.
Applies to vehicles: with speed warning functionDriver messages
Additional messages to assist the driver are displayed
together with the warning symbols in the instrument
cluster.For example, the following driver message will appear if the selector
lever for the automatic gearbox* is not in position P when you
switch off the engine:
Shift to P, otherwise vehicle can roll away. Doors do not lock if
lever is not in P.
The ignition key can only be withdrawn when the selector lever is in
this position. Similar messages will be displayed if other functions
of this kind cannot be carried out.
Driver messages and red symbols
If a red warning symbol appears in the display, it will automatically
be accompanied by the corresponding driver message.
Fig. 24 Instrument
cluster: SET button
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