AUDI A8 2003 D3 / 2.G Technical Features Manual

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Rear lights
SSP282_089
The newly designed rear lights are an ideal
combination of design, function and ultra-
modern technology.
Light-emitting diodes are used for the tail light,
brake light and turn signal indicator functions.
Newly developed "High-performance" bulbs
are employed for the lesser used rear fog light
and reversing light functions.
The high-level third brake light also features
LEDs.
Interior lighting
In addition to the usual interior, reading and
door lights, the new Audi A8 also features new
"ambiente" and door contour lights with
variable functions depending on the lighting
profile selected.
Users can choose between the following
lighting profiles:
– Highway
– City
– Cockpit
– Fond = Rear
Rear light actuation is described in
SSP 287 – Audi A8 ´03 Electrical
Components.
SSP282_111
Brake/tail light on
side panel
– Red LEDs
Turn signal
indicator
– Yellow LEDsBrake/tail light on
boot lid
– Red LEDs
Rear fog light
– 16 W HPV bulb
Reversing light
– 16 W HPV bulb
Reflector

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An optional feature for the Audi A8 ´03 is
4-zone climate control, enabling both driver
and all passengers to make individual
settings independently of the climate control
level selected for the other occupants.
Design and operation
The air conditioning system represents a
more advanced version of the concept
employed in the Audi A8 predecessor model
with 2-zone climate control and features fully
automatic regulation.
Heating/Air Conditioner
The following components are new features
as compared to the systems previously fitted
in the Audi A8:
– Humidity sender G355
– Evaporator outflow temperature sender
G263
– Two versions: 2-zone front climate control
with 12 control motors and 4-zone front
and rear climate control with 15 control
motors
– Rear climate control with electric rear
additional heater as additional equipment
("4-zone system") – rear left and rear right
footwell heater element Z42 and Z43
– Second control and display unit with
4-zone climate control, Climatronic control
unit J255, rear Climatronic control and
display unit E265– Climate control menu in MMI (Multimedia
Interface) for display of climate control set
values and basic settings
– Front and rear seat heating and seat
ventilation
– Heated windscreen Z2
– Energy management control unit J644
The interaction of these components in
coordination with the entire air conditioning
system forms a control loop and permits
comfortable front and rear climate control to
suit all requirements.
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A distinction is made between two air
conditioner unit versions
– 2-zone front and rear climate
control
– 4-zone front and rear climate
control
and three types of control and
display unit
– Air conditioner control panel with
no seat heating/ventilation
– Air conditioner control panel with
seat heating
– Air conditioner control panel with
seat heating and seat ventilation
(identified by part number index).
SSP282_099
Self-diagnosis
Fault diagnosis and measured value blocks
for air conditioner and seat heating system
can be read out by way of address words 08
"Air conditioner/heater electronics" and 28
"Rear climate control". The functions of and
exact procedure for self-diagnosis and
assisted fault-finding with VAS 5051 can be
found in the Heating/Air Conditioner
Workshop Manual for the relevant vehicle
model.
Operating principle
When the ignition is switched on, the
Climatronic control unit J255 starts up with
the same temperature, air distribution and
fresh-air blower speed settings etc. as were
applicable the last time the ignition was
switched off by way of the appropriate key or
using fingerprint recognition.
If fingerprint recognition has been
implemented, this has priority over key
recognition (refer also to SSP 287 – Audi A8 ´03
Electrical Components).
Personalised settings
The following settings can be made for each
climate control zone (front left, right and,
optionally, with 4-zone climate control rear left
and right):
– Left/right temperature
– Air flow
– Left/right air distribution
– Left/right seat heating
– Left/right seat ventilation
– Operating modes (AUTO for driver and front
passenger, temperature-adjustable centre
vents, automatically controlled
recirculated-air mode, ECON)
The heated windscreen can be activated by
way of the air conditioner defrost button or
the air conditioner control unit automatically
switches on the electric heated windscreen if
the appropriate conditions are satisfied
(windscreen defrost or automatic mode on
cold starting).
The Climatronic J255 and heated windscreen
J505 control units communicate by way of the
LIN bus. The Climatronic control unit transmits
the specified windscreen heating power to the
heated windscreen control unit on the LIN bus.
Heating/Air Conditioner
Key recognition takes place in the case of
remote control (radio or key transponder),
with the driver identification control unit
providing the Climatronic control unit J255
with the appropriate information by way of
the CAN bus.
The electrically heated windscreen is only
supplied with the amount of power which can
currently be drawn from the electrical system
without draining the battery. This is
monitored by the energy management
control unit J644.
As is the case with the Audi A4, the
windscreen is heated by applying voltage to a
metallic foil fitted in the glass (refer to
SSP 213).
As in the Audi A4, the air conditioner
compressor is regulated as a function of load
and controlled externally by way of the
compressor regulating valve (refer to
SSP 240). The Climatronic control unit J255 is
connected to the convenience CAN, via
which diagnosis is also performed.
A manual air conditioning system is not
available.

Downloaded from www.Manualslib.com manuals search engine Climatronic control unit J255
SSP282_100
Rear Climatronic control and display unit E265
Air conditioner basic setting
control
Heated rear window
control Front control panel
activation/
deactivation
Seat ventilation
control
Air distribution control
– Up
– Chest vent/centre
– Down Left rotary control/pushbutton
Rotary control +/- for
– Temperature
– Blower speed
– Air distribution up/down
– Seat heating
– Seat ventilation
– Menu control via MMI
Pushbutton
– Synchronisation of driver's
side, passenger's side and
rear settingsDriver's side
control panelPassenger's side
control panel Seat heating controlReset to basic setting/
automatic mode
Temperature sensor
with blowerAir conditioner defrost
and electrically heated
windscreen
Manual recirculated-air
mode control Blower control
Rear left
control panelCentre console/footwell
air distribution controlReset to basic setting/
automatic mode
Rear right
control panel
Left rotary control/pushbutton
Rotary control +/- for
– Temperature
– Chest vent and footwell air
distribution
– Seat heating
– Seat ventilation
Pushbutton
– Synchronisation of driver's
side and passenger's side
settings
Rear left seat heating
controlRear control panel
activation/
deactivation
Rear right seat
ventilation controlRear right seat heating
control
Rear left seat ventilation
control

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3
36
Auto
21,5° C
63
3
The current air conditioner settings are stored
automatically and assigned to the
appropriate remote control key. On vehicles
with Audi one-touch memory (optional), the
current setting is also assigned to the
corresponding fingerprint. Air conditioning system control via MMI
All air conditioning system set values and
basic settings (setup) can be displayed by
way of the MMI. This applies both to the
Climatronic control unit button functions and
to setup.
If the air conditioning system is activated
with the MMI switched on, the air conditioner
function settings can be called up and altered
by way of the multimedia control panel. The
functions indicated in the corners of the
displayed mask are activated using the
softkeys.
Basic setting (setup)
The basic air conditioner settings can only be
altered when the MMI is active. This involves
pressing the SETUP button on the Climatronic
control unit.
The following functions can be selected:
– ECON ON/OFF
– Automatic air recirculation active/inactive
– Synchronisation active/inactive
– Centre vent (temperature-adjustable)
settings between - 3 and + 3
– Auxiliary heater active/inactive
– Auxiliary ventilation active/inactive
– Auxiliary heater/ventilation operating time
15 min./30 min./45 min./60 min.
– Auxiliary heater/ventilation timer status for
timers T1, T2, T3 ON/OFF
– Solar mode active/inactive (solar cells
C20)
– Rear control ON/OFF
The desired settings can be called up and
altered with the driver's/front passenger's
control knob on the Climatronic control unit.
SSP282_112
SSP282_113
low high
Econ
Distribution Seat ventilation
Blower Seat heatingAC - driver
Blower Seat heatingAC setup
Distribution Seat ventilation
Off
Autom. air recirculationOff
Synchron.Off
Centre vent

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Blower unit/air routing
As opposed to the predecessor model, the air
conditioner features an additional evaporator
outflow temperature sender G263. This is
installed in the air duct downstream of the
evaporator and constantly transmits the air
temperature downstream of the evaporator to
the Climatronic control unit J255.
If the left or right centre chest vent is closed
manually, the left/right centre vent control
motor V110/V111 is closed automatically by
the centre left/centre right G347/G348 vent
sensor signal.
Automatically controlled recirculated air
mode
Recirculated air mode is implemented
automatically for a certain period
– If the windscreen washer system switch is actuated or
– In the event of actuation by the air quality sensor G238
Heating/Air Conditioner
When replacing control motors, attention
must be paid to the assignment of the
flaps in the cam plate guides.
G150 Left vent temperature sender
G151 Right vent temperature sender
G263 Evaporator outflow temperature sender
V68
V71 Air-flow flap control motor
V102 Centre vent control motor
V107 Defroster flap control motor
V108 Left footwell flap control motor
V109 Right footwell flap control motor (not illustrated)
V113 Air-recirculation flap control motor
V199 Front right defroster/chest vent shutoff flap control motor
V200 Front left defroster/chest vent shutoff flap control motor
V218 Rear left vent control motor (4-zone system only)
V219 Rear right vent control motor (4-zone system only)Temperature flap control motor

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V199
V68
V219
V102
V218
V108
G263
G151
SSP282_101
G150
V200
V107
V113 V71
Recirculated-air flap
Defrost flap
Right vent
Indirect ventilation/
right
Right footwell
flap
Rear right
footwell flap
Cold-air flap/
centre vent
Rear right warm-air flap
(4-zone system only)
Rear right cold-air flap
(4-zone system only) Rear left cold-air flap
(4-zone system only)
Rear left warm-air flap
(4-zone system only) Centre chest vent temperature/
warm-air flap Fresh-air/air-flow flap
Left footwell
flap
Rear left footwell
flapLeft vent Indirect ventilation/left

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Electric rear additional heater
An electric rear additional heater is fitted
under each front seat in the rear climate
control footwell air ducts.
Heating/Air Conditioner
A further advantage is that independent
temperature regulation (heating) can be
provided for the rear footwell with the 4-zone
system.
A supply of colder air to the rear climate zones
as opposed to the front can be achieved by
way of the centre chest vents.
The temperature can however only be reduced
but not increased via these vents through the
addition of cold air.
As in the predecessor model, two separately
controlled heat exchangers permit the setting
of different temperatures at front left/right.
All occupants can therefore be provided with
individual climate control. Operation
Following a cold start or at low ambient
temperatures, there is insufficient waste heat
in the coolant to warm the rear of the vehicle
by means of a conventional fluid-filled heater.
In addition, the drop in temperature in the rear
air duct is extremely high in the initial phase.
This problem has been solved by integrating
two electric rear additional heaters into the
rear footwell air duct.
These employ electrical energy from the
vehicle electrical system to heat the air
supplied to the passenger compartment.
In this way, the heating function is available
immediately following cold starting.
As was the case with the predecessor
model, in situ heat exchanger
replacement is possible. The procedure
involved is described in the current
Workshop Manual.
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Notes

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Heating/Air Conditioner
SSP282_103 Fresh-air intake duct
temperature sensor G89
Flap control
motor potentiometers
G92, G113, G135, G136,
G137, G138, G139, G140,
G143, G317, G318, G349,
G350, G351, G352
Air quality sensor G238
Left/right vent temperature
sender G150/G151
Centre vent temperature
sender G191
Evaporator outflow temperature
sender G263
High-pressure sender G65
Sunlight penetration
photosensor G107
Solar cells in sunroof C20
System layoutControl unit with display
in dash panel insert J285
MOST busFront information display and
operating unit control unit J523
Rear right footwell heater
element Z43 Rear left footwell heater
element Z42 Fresh-air blower control unit
J126 with fresh-air blower V2Diagnosis CAN
Data bus diagnostic
interface J533
Sunroof electronics
control unit J528 Humidity
sender G355
Humidity sender
heater N340
Climatronic
control unit J255
Convenience CAN
Additional heater
control unit J364 Rear Climatronic control
and display unit E265Energy management
control unit J644Drive system CANEngine control unit J623Front information and display and
operating unit control unit J685
Radiator fan
control unit J293
Radiator fan V7
Air conditioning system compressor regulating valve N280
Flap control motors
V68, V71, V102, V107, V108, V109,
V110, V111, V113, V199, V200, V220,
V218, V219, V221
Coolant circulation pump V50
Left/right heat regulation valve N175/N176
Heated windscreen control unit J505
Heated windscreen Z2
Driver seat/front passenger seat ventilation control unit
J672/J673
Front left/front right heated seat Z45/Z46
Temperature sender for front left/front right seat
G344/G345