sensor AUDI A4 AVANT 2008 User Guide

Clear vision
[ i] Tips
• Do not attach any stickers to the windshield in front of the two
light sensors, as this would interfere with both the automatic oper ­
ation of the headlights and the automatic dimming of the inside
mirror(sl.
• If the vehicle is remotely unlocked and locked
three times in
succession,
leaving home will not turn on the lights a fourth time to
safeguard the battery and lights .
• If you wish to use the coming home/leaving home function regu ­
larly, you can leave it activated at all times without risking perma­
nent strain on the electrical system. As the system is controlled by
light sensors, it wi ll only be energized in darkness.
• Frequent use of the coming home/leaving home function for
approaching and departing a vehicle parked in the dark wil l strain
the battery. This applies particularly if only short distances are
driven between stops . Occas ionally drive longer distances to make
sure the battery is recharged sufficiently.
• If the fog lights have been switched on by the coming
home/leaving home function, they will always be switched off when
you switch on the ignition .•
Instrument panel illumination
The glow of the instruments, displays and the center
console can be adjusted to increase or reduce brightness.
Fig. 76 Instrumen t
panel illumination
Press the"+" button to increase the brightness.
- Press the"-" button to reduce the brightness.
Ignition ON, light switch at @.
With the ignition switched ON, the glow of instrument needles can
be adjusted to appear brighter or dimmer.
Ignition ON, light switch at ;oo~ or io.
With the lights switched on, the brightness of instrument cluster
!i.e . needles, gauges and displays) and center console illumination
can be adjusted.
0 Note
The instrument cluster and center console illumination (gauges and needles) comes on when you switch on the ignition and the vehicle
headlights are off. Be aware of the following difference between
models built to US or Canadian specifications : ..,

Wiper and washer system
r,··· ,
Windshield wiper ~
The windshield wipe r lever controls both the windshield
w ipers and the washer sys te m .
Fig. 8 6 Winds hiel d
w iper le ver
T he windshield wiper lever=> fig. 8 6 has t he following posi­
t ions:
One-touch w iping
- Move the le ve r to p osit ion G) , when you want to wipe t he
windshield
briefly.
Intermittent wiping "V1 (activating rain sensor )*
-Move the lever up to pos ition 0 -
- Move switch © up or down, to adjust the sensitivity of
the rain sensor or to adjust the intermitte nt interval.
Low wiper speed
- Mov e the l ever u p to pos ition G) .
Controls and equip ­
ment
Clear v ision
High wiper speed
- Move the lever up to position @ .
Automatic wiper /washer
- Pull the lever to pos ition ® (towar d the steering w heel)
and ho ld.
Re lease the lever . The washer stops an d the wipers keep
going f or a bout fou r seconds.
Turning off the wipers
- Move the lever back to posit ion @ .
The windshie ld wipers and washer on ly work when the ignition is
turned on .
The rain sensor* is only activated w ith the wiper lever set to position
G). When it starts to rain, the rain sensor will automa tically activate
the intermittent wiping mode .
To reduce the sensitivity of the sensor, move switch @down . To
inc rease the sensitivity, move the switch up. The higher you adjust
the sensitivity, the faster the sensor will react when it senses mois ­
ture on the windshield. The pauses between wiper turns depend not only on the sensitivity setting, but on the vehicle speed as well.
The rain sensor wiper interva ls depend on the sensitivity setting as
we ll as vehic le speed. During brief stops, wiper motion will adjust to
the amount of rain on the w indshield.
When the ignit ion is turned on, the washer jets are heated .
With the low beam headlights switched on, pull the wiper lever
towards you only
briefly to c lean the windshield. Ho lding the wiper
lever would also engage the headlight washer system* each time
you clean the windshield and would drain the washer fluid reservoir
prematurely.
.,
irechnical data

Clear vision
& WARNING
• Wip er blades a re c ruc ia l f or sa fe dri vin g! On ly whe n the y are in
good condition are th ey able to cl ear the window s properly to
p rovi de un comp romi sed vis ibilit y. Wor n or damaged wiper bl ade s
are a safety
hazard => page 88, "In stalling new wiper blades "!
• The rain sen sor i s onl y des igned to assist and s upport the
driver. It rem ain s entirely the driver's respon sibil ity to monit or
o ut side weather con dit ions and to manu ally acti va te the wipe rs as
s o on as rain or drizz le reduce s vi sibility through th e wind shield .
• The windshi eld mu st not b e treat ed w ith water -r e pellent m ate­
rials. T hey can increa se glare u nder poor visibilit y conditi ons such
as w etness, darkne ss, or when the sun i s low on the hori zo n. In
addition , they can caus e the windshield wipers to chatt er.
0 Note
I n freezing or near freezing conditions :
• Always check that the wiper blades are not frozen to the glass
before yo u turn the wipers on. Loosen a wiper b lade which is frozen
in place before operating the w ipers to prevent damage to the wiper
blade or the wiper motor.
• Do not use the wipers to clear a frosted window . Using the
wipers as a convenient ice scraper will destroy the wiper blades .
• Before you take your vehicle to an automatic car wash , make sure
you have the windshield w iper system switched off (lever in position
0), otherwise the windshield wiper system could get damaged in the
car wash if it should suddenly come on .
[ i J Tips
• The rain sensor is part of the interva l wiping system . Turning off
the ignition will also deactivate the rain sensor. To reactivate the sensor, switch off the interval wiping function, then switch it back
on again. •
If you switch off the ignition with the windshield wiper lever sti ll
in the interva l wipe position and then come back a while later and
drive off, the rain sensor will reactivate itself after the vehicle speed
has exceeded 4 mph (6 km/h) .
• Worn or dirty windshield wiper b lades cause smearing which
can affect the opera tion of the rain sensor . Check the conditio n of
your windshield wiper blades regularly .
• Make sure the washer fluid reservoir in the engine compartment
is topped off before going on a long trip . Look
up=> page 291 for
checking and filling the washer container .•
Rear vvindovv vviper (Q
The wiper lever is also used to operate the rear window
wiper and the automatic wiper/w asher function.
F ig . 8 7 Wip er lever:
a cti vating th e rea r
w indo w wipe r an d
was her
The rear win dow wiper a nd the au tomati c wip er/washer
f un ctions are activate d as fo llows:

Disabling auto dimming
- Press button © =>page 90, fig. 92 briefly, -the green
indicator light ® goes out .
Activat ing /reactivating auto dimming
- Press button © briefly, -the green indicator light ®
goes on.
Au toma tic dimming func tion
The automatic dimming function is activated every t ime the ignition
is turned on . The green indicator light is lit to indicate auto dimming
is active.
When dimming is activated, the inside mirror will darken
automati ­
cally
in respo nse to the amount of light striking the mirror (such as
headlights from rearward approaching vehicles) . Even in dimming
mode, the mirror surface turns b right when:
• the interior light is sw itched on
• reverse gear is engaged.
& WARNING
The glass of the ins ide rearview mirror i s layered and contain s an
ele ctrolyte to achie ve it s properties . Be aware of liquid ele ctrolyte
le aking from a broken mirror gla ss. This liquid can cau se irritation
to skin , eye s, and re spir atory sy stem . If you get ele ctrolyte in your
e yes or on your skin , immed iately rinse with plenty of water . If irri­
t a tion per sis ts, s eek medical attention .
0 Note
Liquid electrolyte leaked from a broken mirror glass wi ll damage any
p lastic surfaces it comes in contact with. Clean up spi lled electrolyte
immedia tely w ith c lear water and a sponge.
Controls and equip ­
ment
Clear v ision
[ i ] Tips
• If you switch off the automatic dimming function on the in side
mirror , automatic dim ming of the out side mirrors will l ikewise be
di sabled .
• Check to make sure there are no objects preventing light from
reaching the inside mirror.
• Do not attach any stickers to the windshield in front of the light
sensor, as this would interfere with both the automatic operation of
the headlights and the automatic dimming of the inside mirror.
• Be aware that au tomatic dimming of the inside mirror can on ly
operate properly if the rear window sun blind * is retracted .•
Outside mirrors
The outside mirrors are electrically adjusted (power
mirrors)
Fig . 93 Forwa rd
s ecti on of dri ver 's
ar mr est : pow er mirr or
co ntr ols
....
irechnical data

_______________________________________________ W_ a_ r_ m __ a_n _ d_ c_ o_ ld __ lJIII
Moreover, the a ir conditioning switches on again whenever you
press the fan speed or temperature buttons. •
Automatic air recirculation [@, I
If outside air is polluted, an air quality sensor in the
vehicle will automatically switch on the air recirculation .
Switching on air re circul ation
-Press[ ~)~ page 126, fig. 137 .
Swit ching off air r ecircul ati on
-Press~ again, or
- press [AUTO), or
-
press[ ®].
The automat ic air recirculation mode should normally be left
switched on at a ll times.
The system is ready to operate approximately 30 seconds after you
tu rn on the ignition or start the vehicle . Fresh air enters the vehicle
only during this initialization period .
If the
a ir quality sen sor in the air condit ion ing system detects
exhaust fumes in the outside air, the contro l unit wil l either pass the
incom ing a ir throug h the pol lution filter, or automat ical ly switch on
the air recirculation.
The air conditioning system wi ll automatically switch on the air
recirculation if it senses that the outside air is very po lluted . At the
same time, it will not allow any outside air to enter the vehic le until
the air quality has improved .
The air recircula tion opera tes for a maximum of
12 minu tes. If th e
windows start to fog up whi le the a ir rec irculation is on, press
[ @1
Under certain operating conditions (for example, if [@ ) or [Qi] are
pressed) the air recircu lation automatically switches off. If "ECON"
Controls and equip ­
ment
is pressed, or if the temperature is below 18° F (-8 °C), the air recir­
culat ion will operate only for
1 2 seco nds .•
Adjusting the fan speed 8 G
The automatically selected fan speed can be increased or
decreased.
D
D
D
D
D
D
F ig . 138 Fa n sp ee d
but tons a nd di spl ay
indi cation
- Press the 8 or G b uttons in the center of the contr ol
pane l~ fi g. 1 38 to adjus t the fa n speed to yo ur comfor t.
The air condit ioning system automa tica lly regu lates the fan speed
in response to the interior tempera ture . However, you can also
adjust the fan speed manua lly . A lin e of sma ll bars in the center
display above the fan control buttons will retreat or extend to reflect
your adjustments to the fan speed. •

On the ro ad 11111 ---------------------------------------------------------------~
acoustic park assist
A pplies to vehicles : with 4 -c h an nel a cou sti c par k ass is t
Rear acoustic park assist
The rear acoustic park assist warns you of obstacles or
objects behind your car.
How it wor ks
The acoustic park assist warning system (4 -channel acoustic park
assist) uses ultrasonic sensors to warn you when you are
backing
your vehicle close to an obstac le . The system 's 4 sensors are located
inside the rear bumper.
A cti va ting
The rea r acoustic park ass ist is activa ted whenever you shift into
Re verse . You will hear a warn ing tone when the system is on.
Reverse
With the car backing up in reverse gear, the collision warning sound
se ts in at the fo llowing
approximate d istances to obstacles:
st raight a ft 5ft(
1.5ml
a ngl ing aft of f ve hicle corners 2 ft (0.6 ml
As the distance shr inks, the time interval between the audible tones
grows shorter.
The sound changes to a continuous tone as soon as the remaining
d istance to an obstacle c loses to less than about 1 ft. (0.3 ml. The
steady tone cautions you that you have backed up hazardously
close and you risk co llis ion by back ing up any furt her .
Malfunction s in the system
If a warning tone is audible for about five seconds when you turn on
the ignition, there is a ma lfunction in the system . Have the prob lem
corrected by your authorized Aud i dealer.
Controls and equip ­
ment
Keep the sensors in the rear bumper clean and free from ic e so t hat
the acoustic park assist system can funct ion proper ly .
& WARNING
• Sensors have dead spaces in which object s cannot be
detected . Be especiall y alert for small ch ildren and animals , since
they are not always dete cted by the sensor s.
• The acousti c pa rk assist system is not a substitute for the
driver's own caution and alertne ss . Ultimate re sponsibility alway s
remains w ith the driver dur ing parking and s imilar maneuvers .
Alway s watch where you are driving _
0 Note
• Remem ber t hat low obstac les for wh ich a warning has already
been issued may "dive" below the system's sensing zone if the
veh ic le is be ing bac ked up cl oser. In this case, the warning sound
shutting off does
not indica te that you have cleared the obstacle .
Instead , impact is imminent.
• Objects such as trai ler hitches, barrier chains, narrow posts or
f ences covered by a th in laye r of pa int may not always be detected
by the system . T hey can sti ll damage your vehic le without a
warning.
[ i ] Tips
Keep the sensors in the rear bumper clean and free of snow and ice
so that the acoust ic park ing ass ist system can function properly .•

_________________________________________________ s_a _f_e _t .!,y _ b
;,;;..;; e.;.lt ;;,,; s;;...__1111
& WARNING
Always read and heed all WARNINGS and other important informa­
tion
=> page 180.
[ i] Tips
The seat height adjustment on the front seats can also be used the adjust the position of the safety belts .•
Improperly worn safety belts
Incorrectly positioned safety belts can cause severe inju­
nes.
Wearing safety belts improperly can cause serious injury or
death. Safety belts can only work when they are correctly
positioned on the body. Improper seating positions reduce
the effectiveness of safety belts and will even increase the
risk of injury and death by moving the safety belt to critical
areas of the body . Improper seating positions also increase
the risk of serious injury and death when an airbag deploys and strikes an occupant who is not in the correct seating position. A driver is responsible for the safety of all vehicle
occupants and especially for children. Therefore:
- Never permit anyone to assume an incorrect sitting posi­
tion in the vehicle while
traveling =>& .
& WARNING
Improperly worn safety belts increase the risk of serious personal
injury and death whenever a vehicle is being used.
• Always make sure that all vehicle occupants are correctly
restrained and stay in a correct seating position whenever the
vehicle is being used.
Controls and equip­ ment Safety first Vehicle operation
& WARNING
(continued)
• Always read and heed all WARNINGS and other important infor­
mation
=> page 180. •
Safety belt tensioner
How safety belt pretensioners work
In front, side and rear collisions above a particular
severity, safety belts in use are tensioned automatically.
The safety belts are equipped with safety belt pretensioners . The
system is activated by sensors in front, side and rear collisions of
great severity. This tightens the belt and takes up belt
slack=> & in
"Care, service and disposal of safety belt pretensioner". Taking up
the slack helps to reduce forward occupant movement during a collision .
0 Note
Never let the belt remain over a rear seat back that has been folded
forward. The rear belt pretensioner will be activated unnecessarily
in a collision and then has to be replaced .
[ i] Tips
The safety belt pretensioner can only be activated once.
• In minor frontal, side and rear -end collisions, in a rollover and in
accidents involving very little impact force, the safety belt preten­
sioner are not activated.
• When the safety belt pretensioner is activated, a fine dust is
released. This is normal and is not caused by a fire in the vehicle.
• The relevant safety requirements must be observed when the
vehicle or components of the system are scrapped. A qualified
deal -_,,.
Vehicle care Do-it-yourself service Technical data

___ A_ ir_b _ a_ g=- s--=- y_s _t _e _m _________________________________________________ _
&, WARNIN G (continu ed )
• The inflating airbag will hit the child s afety seat or infant
car rier with gre at for ce and will sma sh the child safe ty se at and
c hild agai nst the ba ckre st, center arm re st, door , or roof .
• Alwa ys in sta ll re arw ard -f aci ng child re str aint s in the b ack se at .
• If you mu st in stall a rearw ard facing child safety seat on the
front p assenger se at be cause of e xce pti ona l ci rc um stan ce s a nd
the PASSENGER AIR BAG OFF light doe s not come on and stay on ,
immedi atel y insta ll the re ar-f a cing child s afet y s ea t in a re ar
se ating position and h av e the airb ag sy stem inspe cted by your
Audi dealer .
& WARNING
If, in e xception al c ir cum sta nces, you mu st in sta ll a forward -f ac in g
c hild re straint on the front p assenger 's seat:
• Alway s mak e sure the forward-f acing seat ha s been designed
and certified by it s manufacturer for u se on a front seat with a
p asseng er front and side airb ag .
• Never put the forw ard -fa cing child re straint up again st or very
near the instrument panel.
• Alway s move the p assenger seat into it s re armost position in
the se at's fore and aft adju stment range , as far a way from the
a irbag a s pos sible , before installing the forward -f a cing child
rest raint . The ba ckrest must be ad justed to an upright po sitio n.
• Make sure that the PASSENGER AIR BAG OFF light come s on
a nd stay s on all th e time whenever the ignit ion i s swi tched on .
•
Advanced Airbag System components
The front passenger seat in your vehicle has a lot of very impo rtant
parts of the Advanced A irbag System in it . These parts include the
we ight -sensing mat , sensors, wiring, brackets , and more. The func -tion of the system in the front passenger seat is checked by the e
lec ­
tronic contro l unit w hen t he ignit ion is on . The co ntrol uni t monitors
the Advanced Airbag System and turns the airbag indicator light on
whe n a malfunction i n the system components is detected. T he
function of the airbag ind icator light is described in greater detai l
below. Because the front passenger seat contains important parts
o f the Advanced Airbag System, you must take care to prevent it
from being damaged . Damage to the seat may prevent the
Advanced Airbag for the front passenger seat from do ing its job in
a crash .
The front Adva nc ed Airbag S ystem consi sts of th e
following :
• Crash sensors in the front of the ve hicle that measure veh ic le
acce leration/deceleration to provide information to the Advanced
A irbag System about t he severity of t he crash .
• An electronic control unit, with integrated crash sensors for front
and side impacts. The control unit "dec ides" whethe r to fire the
front airbags based on the information received from the crash sensors . The control unit also "dec ides" whether the safety be lt
pretensioners should be activated.
• A dual -stage Advanced Airbag with gas generator for the driver
inside the steering wheel hub.
• A dual-stage Advanced A irbag and gas generator inside the
instrument pane l for the front passenger .
• A we ight -sensing mat under the upholstery padding of the front
passenger seat cushion that measures the tota l weight on the seat .
T he information registered is sent continuously to the electronic
control un it to regu late dep loyment of the front Advanced Airbag on
the passenger side .
• An airbag monitor ing system and indicator light in the instru ­
ment
cluster=> page 198 .
• The PASSENGER AIR BAG OFF light comes on and stays on in t he
center of the instrument panel
=> page 199, fig . 180 and te lls you
when the fron t Advanced Airbag on the passenger side has been
turned off.
~

Airbag system 111111
-------------------------------------------- -=-:~--___.
• A sensor below the safety belt latch for the front seat passenger
t o m easure the tens io n on t he sa fety be lt. T he tension on the safe ty
belt and the weight registered by the weight -sensing mat help the
contr ol unit "decide" whe the r the front ai rbag for the fron t
passenger seat should be turned off or
not=> page 189, "Child
r est ra ints on the front seat - some important th ings to know".
• A sensor in the safety belt latch for the driver and for the front
seat passenge r that senses whether t hat safety bel t is la tched or no t
and transmits this information to the e lectronic control unit.
& WARNING
Damage to the front pas senger seat can pre vent the front airbag
from working properly.
• Improper repair or disassembly of the front passenger and
driver seat will prevent the Advanced Airbag System from func ­
tioning properly .
• Repairs to the front passenger seat must be performed by qual ­
ified and properly trained workshop personnel .
• Never remove the front pa ssenger or driver seat from the
vehi cle .
• Ne ver remo ve the upholstery from the front passenger seat .
• Never disassemble or remove parts from the seat or disconnect
wires from it .
• Never carry sharp objects in your pockets or place them on the
seat . If the weight -sen sing mat in the passenger seat i s pun ctured
it cannot work properly.
• Never carry things on your lap or carry objects on the
passenger seat . Such items can increase the weight registered by
the weight -sensing mat and send the wrong informat ion to the
airbag control unit .
• Never store items under the front passenger seat . Parts of the
Advanced Airbag System under the passenger seat could be
d amaged , preventing them and the airbag system from working
properly.
Controls and equip­ ment Safety first
Vehicle operation
& WARNING (continued )
• Never place seat covers or replacement upholstery that have
not been specifically appro ved by Audi on the front seat s.
• Seat covers can prevent the Advanced Airbag System from
recognizing child restraint s or occupants on the front passenger
seat and prevent the side airbag in the seat backrest from
deploying properly.
• Never use cushions, pillows , blankets or similar items on the
front passenger seat. The additional padd ing will prevent the
weight-sensing mat in the seat from accurately registering the
child restraint or person on the seat and prevent the Ad vanced
Airbag System from functioning properly .
• If you mu st use a child re straint on the front pas senger seat
and the child restraint manufacturer's instru ctions require the use
of a towel , foam cu shion or something el se to properly position
the child restraint , make certain that the PASSENGER AIR BAG OFF
light comes on and stays on whenever the child restraint i s
installed on the front passenger seat.
• If the PASSENG ER AIR BAG OFF light does not come on and stay
on , immed iately install child re straint in a re ar seat ing position
and have the airbag sy stem inspected by your Audi dealer . •
How the Advanced Airbag System
components work together
The front Advanced Airbag System and the side airbags supplement
the prote ction off ered by the fro nt three -p oi nt safe ty belts with
pretensioners and load limiters and the adjustable head restra ints
to help reduce the risk of injury in a wide range of accident and
crash situations. Be sure to read the important informat ion about
safety and heed the WARNI NGS in this chapter.
Dep loyment of the Adva nced Ai rbag Sys tem a nd th e activation of
the safety belt pretensioners depends on the dece leration
measu red by the crash senso rs and registered by the electro nic _.,
Vehicle care Do-it-yourself service Technical data

__________________________________________________ A_ i_ r _b _a-' g=- s_ y=-- s_t _e _m ______ lfflll
PASSENGER AIR BAG OFF light
N
-M -J., a, cc
Fi g. 18 0 Sec tion fr om
t h e i nstr um ent pa nel:
P ASSE NG ER AI R BA G
OFF lig ht
The PASSENGER AIR BAG OFF light is located in the center o f the
ins trumen t panel
=> fig . 180 .
The PASSENGER AIR BAG OFF light wil l come on and stay on to te ll
you when the front Advanced Airbag on the passenger side has been turned off by the electronic control unit. Each time you turn on
the ign it ion, the
PA SS ENGER AIR BA G OFF light wi ll fl as h for a few
seconds and :
• will stay on if t he front passenger seat is not occupied,
• will stay on if there is a small child or chi ld restraint on the front
passenger seat,
• will go out if the front passenger seat is occupied by an adult as
registered by the we ight -sens ing mat.
The
PA SS ENGER AIR B AG OFF light mu st come on and stay on if the
ignition is on and
• a car bed has been instal led on the front seat, or
• a rearward -facing chi ld restraint has been installed on the front
passengerseat,or
Controls and equip­ ment Safety first
Vehicle operation
• a forward -facing child restraint has been instal led on the front
passenger seat, or
• the weight register ed on the front passenger seat is equa l to or
less than the combined weigh t of a typica l 1 year-old restrained in
one of the rear -facing or forward -facing infant restraints listed in
Federa l Motor Veh ic le Safe ty S tandard
208 with wh ich the Advanced
Airbag System in your vehicle was certified .
If the front passenger seat is not occupied, the front airbag will not
dep loy, and the
PA SS ENGER AIR BAG OFF light will stay on . Never
insta ll a rearward -facing child restraint on the front passenger seat,
the safest place for a child in any kind of ch ild restraint is at one of
the seating positions on the rear
seat => page 189, "Ch ild restraints
on the front sea t-some important things to know"
and => page 210,
"Chi ld Safety" .
If the PASSENGER AIR BAG OFF light comes on when one of the
condit ions listed above is met , be sure to check the light regu lar ly
to make certain that the
PA SSENGER AIR BAG OFF light stays on
cont inuously whenever the ignition is on . If the PASSENGER AIR
BAG OFF light does not appear and not stay on all the time , stop as
soon as it is safe to do so and
• reactivate the system by turning the ignition off and then turning
it on again;
• remove and reinstall the ch ild restraint. Make sure that the child
res tra int is proper ly instal led and t hat t he sa fety be lt for the front
passenger seat has been correctly routed around the child restraint
as described in the chi ld restraint manufacturer's instructions;
• make sure that the convertible locking feature on the safety belt
for the front passenger seat has been activated a nd that the safety
belt has been pulled t ight . The belt must not be loose or have loops
of slack so t hat t he sensor below t he safety belt latch on the seat can
do its job
=> page 220.
• make s ure that th ings that may inc rease the we ight of the child
and child safety seat are not being transported on the front
passenger seat;
Vehicle care Do-it-yourself service Technical data