2009 AUDI A4 CABRIOLET wiring

Airbag system -----------------=~-
& WARNING (continued)
• If you must install a rearward facing child safety seat on the
front passenger seat because of exceptional circumstances and
the PASSENGER AIR BAG OFF light does not come on and stay on,
immediately install the rear -facing child safety seat in a rear
seating position and have the airbag system inspected by your
Audi dealer.
_& WARNING
If, in exceptional circumstances, you must install a forward-facing
child restraint on the front passenger's seat:
• Always make sure the forward-facing seat has been designed
and certified by its manufacturer for use on a front seat with a
passenger front and side airbag .
• Never put the forward-facing child restraint up against or very
near the instrument panel.
• Always move the passenger seat into its rearmost position in
the seat's fore and aft adjustment range, as far away from the
airbag as possible, before installing the forward-facing child
restraint. The backrest must be adjusted to an upright position.
• Make sure that the PASSENGER AIR BAG OFF light comes on
and stays on all the time whenever the ignition is switched on. •
Advanced Airbag System components
The front passenger seat in your vehicle has a lot of very important
parts of the Advanced Airbag System in it. These parts include the
weight-sensing mat, sensors, wiring, brackets, and more. The func­
tion of the system in the front passenger seat is checked by the elec­
tronic control unit when the ignition is on. The control unit monitors
the Advanced Airbag System and turns the airbag indicator light on
when a malfunction in the system components is detected. The
function of the airbag indicator light is described in greater detail
Controls and equip­ ment Safety first Vehicle operation
below.
Because the front passenger seat contains important parts
of 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 doing its job in
a crash.
The front Advanced Airbag System consists of the
following:
• Crash sensors in the front of the vehicle that measure vehicle
acceleration/deceleration to provide information to the Advanced
Airbag System about the severity of the crash.
• An electronic control unit, with integrated crash sensors for front
and side impacts. The control unit "decides" whether to fire the
front airbags based on the information received from the crash sensors. The control unit also "decides" whether the safety belt
pretensioners should be activated.
• An Advanced Airbag with gas generator for the driver inside the
steering wheel hub.
• An Advanced Airbag with gas generator inside the instrument
panel for the front passenger .
• A weight-sensing mat under the upholstery padding of the front
passenger seat cushion that measures the total weight on the seat.
The information registered is sent continuously to the electronic
control unit to regulate deployment of the front Advanced Airbag on
the passenger side.
• An airbag monitoring system and indicator light in the instru ­
ment cluster ~
page 179.
• The PASSENGER AIR BAG OFF light comes on and stays on in the
center of the instrument panel~
page 180, fig. 174 and tells you
when the front Advanced Airbag on the passenger side has been
turned off .
• A sensor below the safety belt latch for the front seat passenger
to measure the tension on the safety belt. The tension on the safety
belt and the weight registered by the weight -sensing mat help the
control unit "decide" whether the front airbag for the front _,.
Vehicle care Do-it-yourself service Technical data

__________________________________________________ A_ i_ r _b _a...; g::- s_ y=--- s_t _e _m ___ __
& WARNING (continued )
airbag dur ing braking or in a sudden maneuver . Objects ne ar the
airbags can become proje ctiles and cau se injury , particularly when
the seat is reclined .
• Never tilt the front passenger seat backrest forward when the
vehicle is moving . An inflating airbag will force the backrest back­
ward and can injure rear seat occupants.
_& WARNING
The fine dust created when airbags deploy can cause breathing problems for people with a history of asthma or other breathing
conditions.
• To reduce the risk of breathing problems, those with asthma or
other respiratory conditions should get fresh air right away by
getting out of the vehicle or opening windows or doors.
• If you are in a collis ion in which airbags deploy, wash your
hands and face with mild soap and water before eating.
• Be careful not to get the dust into your eyes , or into any cuts or
scratches .
• If the residue should get into your eyes, flush them w ith
water. •
Monitoring the Advanced Airbag
System
Airbag monitoring indicator light :~
Two sep arate in dica tors m onitor the fu ncti on of th e
Adv anced A irba g Sys tem: the airbag moni tor ing in dica to r
l ight and t he
PASSENGER AIR BAG OFF light.
The Advanc ed A ir b ag S yst em (includ ing the e lec tronic co ntro l unit,
sensor c ircuits and system wiring) is monitored continuously to
Controls and equip­ ment Safety first Vehicle operation make sure that it is functioning properly whenever the ignition is on
.
Eac h tim e you tu rn on t he ignit io n, th e airbag monitoring ind ica tor
light
fl wi ll come on for a few seconds (self diagnostics) .
The system must be inspected when the indicator l ight ~:
• do es not com e on when the ig nit ion is sw itch ed on,
• does not go out a few seconds after you have switched on the
i gni tion , or
• comes on while driving.
I f an a irbag s ystem malfu ncti on is detec ted , the indi cator light will
first start flash ing to catch the driver's attention and then sta y on
co nti nuou sly to serve as a constant r eminder to h ave the sys tem
inspected immediately.
If a malf unctio n occurs that t urns the front airbag on the passenger
s id e off , the PASS ENGER AIR BAG OFF light w ill come on a nd s ta y on
whenever the ig nition is on.
_& WARNING
An airbag system that is not functioning properly cannot provide
s upplemental protect ion in a frontal crash .
• If the airbag indicator light comes on , it means that there may
be something wrong with the Advanced Airbag System . It is
possible that the airbag will inflate when it is not supposed to, or
will not inflate when it should .
• Have the airbag system inspected immediately by your Audi
dealer. •
Vehicle care Do-it-yourself service Technical data

Trailer lights
Trailer lights must meet all regulations. Be sure to check with your autho rized Audi dealer for correct wiring , switches and relays .
Mirrors
If you are unable to see the traffic behind you using the regular
outside mirrors, then you
must install extended mirrors. It is impor ­
tant that you always have clear vision to the rear .
& WARNING
After removing the trailer hitch, do not store it in your vehicle. In
case of sudden braking, the hitch could fly forward and injure you
or your passengers .
.1
Operating instructions
Maximum trailer weight
A trailer for your vehicle is limited to a typical class 1 or class 2
trailer .
Trailer load distribution
Be sure the load in the trailer is held securely in place to guard
against shifting, be it forward, backward or sideways.
Never allow a passenger to ride in a trailer~&, in "Driving instruc­
tions".
Tire pressure
When towing a trailer, inflate the tires of your vehicle to the cold tire
pressure listed under "Full load" on the sticker on the right door­
jamb. Inflate trailer tires to trailer and tire manufacturers' specifica­
tions.
Controls and equip­ ment Safety first Vehicle operation
Trailer towing
Lights
The
headlight settings should be checked with the trailer attached
before driving off. Adjust as necessary so that you can see the road
ahead but not blind on -coming traffic.
Check proper working of vehicle and trailer lights .
Safety chains
Be sure trailer safety chains are properly connected from the trailer
to the hitch on the vehicle. Leave enough slack in the chains to
permit turning corners. When you install safety chains, make sure
they will not drag on the road when you are driving.
The chains should cross under the trailer tongue to prevent it from
dropping in case of separation from the hitch .•
Driving instructions
Driving with a trailer always requires extra care and
consideration.
To obtain the best possible handling of vehicle and trailer,
please note the following:
Do not tow a loaded trailer when your car itself is not
loaded.
- Be especially careful when passing other vehicles.
Observe speed limits.
Do not drive at the maximum permissible speed.
- Always apply brakes early.
Monitor the temperature gauge.
Vehicle care Do-it-yourself service Technical data