light AUDI A6 2005 C5 / 2.G Electrics System Training Manual

Downloaded from www.Manualslib.com manuals search engine The new Audi A6 – the most progressive vehicle
takes the lead.
The new Audi A6 consistently adopts the highly
networked electronic architecture, which is already
used in the Audi A8. Overall, new technologies allow
the A6 to match up with its "model" vehicle, the Audi
A8. Features, which were previously reserved for
luxury vehicles, are now also available in the top-
class segment.
In combination with these diverse capabilities,
the underlying technology has, of course,
been enhanced considerably.
The use of the most modern network technologies,
such as CAN, LIN, MOST and Bluetooth, and the
related distributed vehicle functions signals the
arrival of a new generation of vehicle electrics in
this class.
Some of these are safety-related features, such as
the combined rain/light sensor or the pivoting
cornering headlight. Comfort features of the top
class, such as the MMI operating system or
sophisticated functionalities for the mobile
baseplate, which is available ex-works, are part and
parcel of these new saloons.
The new Audi A6 has everything that is needed to
become the Number One model in the top-class
range.
It combines many different, attractive components
to form one unit. Design and performance go
hand-in-hand. The new Audi A6 will take over
as the most progressive vehicle.
The Audi A6 – the most progressive vehicle takes the lead
Number One: With Design & Performance

Downloaded from www.Manualslib.com manuals search engine Note ReferenceNote Reference
Control unit installation positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Bus topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installation positions of fuses and relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Overview
Convenience electrics
Control unit for power management J644 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Access and start authorisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Immobiliser and component protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
External lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Control unit in dash panel insert J285 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Control unit for on-board power supply J519 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Control unit 2 for on-board power supply J520 . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Central control unit for convenience system J393 . . . . . . . . . . . . . . . . . . . . . . . . 55
Door control units J386 - J389 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Control units for seat adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Infotainment
Multimedia interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Antenna systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Control unit for front information J523 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Sound systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Available telephone systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
The Self-Study Programme provides information on the fundamentals of design and function of new vehicle
models, new vehicle components or new technologies.
The Self-Study Programme is not a Workshop Manual!
Specified values serve only to make the information easier to understand and relate to the software version
that was valid at the time the Self-Study Programme (SSP) was created.
For maintenance and repair work, please make sure to use the current technical documentation.
Contents

Downloaded from www.Manualslib.com manuals search engine 4
Overview
1 Auxiliary heating control unit J364
2 Control unit for ABS with EDL J104
3 Control unit for distance control J428
4 Transmitter unit in wheel well for tyre pressure
monitoring, front left G431
5 Control unit for on-board power supply J519
6 Door control unit, driver's side J386
7 Control unit for access and
start authorisation J518
8 Control unit in dash panel insert J285
9 Control unit for steering column electronics J527
10 Control unit for telephone, telematics J526
Telephone transmitter and receiver R36
11 Engine control unit J623
12 Climatronic control unit J25513 Control unit for seat adjustment with steering-
column adjustment memory J136
14 Level control unit J197
Control unit for headlight range control J431
Control unit for tyre pressure monitoring J502
Control unit 2 for onboard power supply J520
Control unit for display and operating unit for
front information J523
Data bus diagnosis interface J533
Antenna read-in unit for keyless access
authorisation J723
15 CD changer R41
CD ROM drive R92
16 Door control unit, rear left J388
17 Airbag control unit J234
Control unit installation positions

Downloaded from www.Manualslib.com manuals search engine 6
Bus topology
Overview
NOX sensor
J583
Rotation rate sensor
G202
Seat occupied
recognition
J706
Power module
for left headlight
J667
Power m odule for
right headlight
J668
Level control
J197 Electric parking
and hand brake
J540 Headlight range
control
J431 Automatic
transmission
J217 Airbag
J234 ABS with EDL
J104 Engine electronics 1
J623 Diagnosis connection
T16Control unit in dash
panel insert
J285Distance control
J428
Data bus diagnosis
for data bus
J533
Door control unit,
driver’s side
J386
Door control unit,
passenger’s side
J387
Door control unit,
rear left
J388
Door control unit,
rear right
J389
Seat adjustment
with memory
Steering column
adjustment
J136
Seat adjustment
with memory,
passenger’s side
J521
Trailer detection
J345
Steering column
electronics
J527
Multi-function
steering wheel
J453 Steering-angle
sensor
G85Power management
J644
Auxiliary heating
J364
Parking aid
J446
On-board power
supply 2
J520
Access and
start authorisation
J518
On-board power
supply
J519
Centr. contr. unit for
convenience system
J393
Climatronic
J255
Tyre pressure
monitoring
J502

Downloaded from www.Manualslib.com manuals search engine 7
326_027
Display and
operating unit for
front information
J523Te l e p h o n e
transmitter and
for telephone
R36
CD changer
R41
Digital
sound package
J525
Switch for
access and
start authorisation
E415Antenna read-in
unit for keyless access
authorisation
J723
Wiper motor
J400Sensor for rain and
light detection
G397
Passenger
compartment
monitoring
G273Alarm horn
H12
Fresh air fan
J126Refrigerant pressure and
refrigerant temperature
G395
Tr a n s m i t t e r,
front left
G431Tr a n s m i t t e r,
front right
G432Tr a n s m i t t e r,
rear left
G433Transmitter,
rear right
G434Antenna, rear
R96 Te l e p h o n e /
telematics
J526Handset
for telephone
R37
Navigation
with CD drive
J401
TV tuner
R78
Radio module
RVoice input
J507
MOST bus
CAN Instrument cluster
CAN Diagnosis
CAN Drive
CAN Convenience
CAN Distance control
LIN bus
Various sub-bus systems
Wireless transmission
– Bluetooth signal

Downloaded from www.Manualslib.com manuals search engine Convenience electricsFunction diagramLegend
E369 Central locking button for outer door handle,
driver’s side*
E370 Central locking button for outer door handle,
passenger’s side*
E371 Central locking button for outer door handle,
rear left*
E372 Central locking button for outer door handle,
rear right*
E408 Button for access and start authorisation
E415 Switch for access and start authorisation
F272 Outer door handle switch, driver’s door*
F273 Outer door handle switch, passenger’s door*
F274 Outer door handle switch, rear left*
F275 Outer door handle switch, rear right*
F305 Switch for gearbox position P**
G415 Sensor for outer door handle contact,
driver’s side*
G416 Sensor for outer door handle contact,
passenger’s side*
G417 Sensor for outer door handle contact,
rear left*
G418 Sensor for outer door handle contact,
rear right*
J53 Starter relay
J329 Voltage supply relay, terminal 15
J386 Door control unit, driver's side
J387 Door control unit, passenger's side
J388 Door control unit, rear left
J389 Door control unit, rear right
J518 Control unit for access and
start authorisation
J623 Engine control unit
J694 Voltage supply relay, terminal 75x
J695 Starter relay 2
J723 Antenna read-in unit for keyless access
authorisation*
R47 Antenna for central locking and
anti-theft warning system
R134 Antenna on driver’s side for access
access and start authorisation*
R135 Antenna on passenger’s side for access
access and start authorisation*
R137 Luggage compartment antenna for access
access and start authorisation*
R138 Passenger compartment antenna 1 for
access and start authorisation*
* only for vehicles with Advanced Key
** only for vehicles with automatic transmission
1 Terminal 50 (to starter B)
2 CAN Convenience High
3 CAN Convenience Low
4 P/N signal from control unit for
automatic transmission J217**
5 Terminal 58s (lighting)*
6 Signal from brake light switch F*
Positive supply
Input signal
Output signal
Ground
Bi-directional line
13
Access and start authorisation
Start request
Ulock

Downloaded from www.Manualslib.com manuals search engine 20
– Reading in position P of the automatic
transmission from the switch for gearbox
position P F305:
The signal is used to activate the integrated,
magnetic ignition key anti-removal lock. If the
vehicle battery is flat, the key can be removed by
pressing the mechanical emergency release.
– Reading in the information from the button for
access and start authorisation E408 (only for
vehicles with Advanced Key):
Fo r s a fe t y r e as o n s , t h e p o s i t i o n s o f t h e b u t to n fo r
access and start authorisation are evaluated by
the switch for access and start authorisation.
–
– Reading in the information from the antenna for
central locking and anti-theft warning
system R47:
The switch for access and start authorisation
passes the data, which the vehicle key sends via
remote control, on to the control unit for access
and start authorisation. The control unit
evaluates the data.
– Reading in the signal from the brake light
switch F (only for vehicles with Advanced Key):
To start the vehicle using the button for access
and start authorisation, the brake pedal must be
actuated.
– Exchanging data with the key using the
integrated read coil:
If a key is inserted into the switch for access and
start authorisation (= S contact on), the
electronics system transmits electric power into
the key via the read coil. The key then sends the
key identification into the switch via the
transponder and the read coil. This sends the
information to the control unit for access and
start authorisation.
Convenience electrics
326_069 326_068
326_065

Downloaded from www.Manualslib.com manuals search engine 27
1 The driver puts his/her hand into the finger well
of the door handle. The sensor for outer door
handle contact G415 sends the information
"Finger in finger well" to the antenna read-in unit
for keyless access authorisation J723.
2 The antenna read-in unit sends an alarm signal
to the vehicle key via the antenna for access and
start authorisation R134.
3 The antenna read-in unit sends a signal to the
vehicle key via all the antennae for access and
start authorisation.
4 Based on the signals, the vehicle key determines
the position on the vehicle and sends
information to the antenna for central locking
and anti-theft warning system R47.
5 The antenna for central locking and anti-theft
warning system receives the information.
The information is forwarded by the switch for
access and start authorisation E415 to the
control unit for access and start
authorisation J518, where it is evaluated.6 The control unit for access and start
authorisation sends the information "Opening
vehicle" on to the central control unit for the
convenience system J393 and to the door control
unit, whose door handle initiated the key query.
7 The door control unit, which received the
instruction from the control unit for access and
start authorisation, activates the lock unit, which
unlocks the door.
8 The central control unit for the convenience
system J393 sends the information "Opening
vehicle – Advanced Key" to CAN Convenience.
9 The normal unlocking process takes place.
This involves disarming, unlocking,
acknowledgement flashing and switching on of
the interior light. In addition to
acknowledgement flashing, the control unit for
access and start authorisation also sends the
lock status to the vehicle key via the switch for
access and start authorisation and the antenna
for central locking and anti-theft warning
system R47.

Downloaded from www.Manualslib.com manuals search engine 32
External lights
Front headlights
Three different front headlights are used in the
Audi A6 ’05:
– Halogen headlights
–Bi-xenon headlights
–Adaptive light
Halogen headlights
Halogen headlights come as standard.
The following lamps are fitted in the halogen on the
vehicle equipment:
– W5W lamp for parking light
– H1 lamp for high beam headlight and headlight
flasher
– H7 lamp for dipped beam headlight and dimmed
as a daytime driving light
– An orange PY21W bulb as the direction indicator
light
The daytime driving light in the halogen headlight is
only available for Canada and the Northern
countries (Scandinavia). It is active when
terminal 15 is switched on and the parking light or
dipped beam light is off.
The following country-specific variants exist:
– The daytime driving light is part of the fog lights
for Canada and
– 3457NA flasher lamps are used for USA and
Canada.
A manual headlight range control system – with
potentiometer – is installed for halogen headlights.
Convenience electrics
326_087
326_149
12 3 4 5
1W5W lamp
2H1 lamp
3H7 lamp
4 PY21W lamp
5D2S lamp

Downloaded from www.Manualslib.com manuals search engine 33
Bi-xenon headlights
Bi-xenon headlights are installed with the
"XenonPlus" option.
The following lamps are fitted in the bi-xenon
headlight:
– A blue W5W lamp for the parking light.
The colour of the parking light thus corresponds
to the xenon light.
– A D2S lamp for high beam headlight, headlight
flasher and dipped beam headlight. The covers
fo r d i p p ed b e am a re al s o a c t i v at e d fo r h i gh b ea m
and headlight flasher operation.
– A P21W lamp for the daytime driving light.
This comes on dimmed to 90 %.
– A PY21W bulb coated with a reflecting layer of
silver is used as the direction indicator light.
Only longlife lamps are used. A super-longlife
lamp is used as the daytime driving light.
The following country-specific variants exist:
– No daytime driving lamp is fitted for Japan.
– 3457NA flasher lamps are used for USA and
Canada.
The headlights are changed over to left-hand drive
via a lever on the projection module.
A dynamic headlight range control system is
installed for bi-xenon headlights.
The dynamic headlight range control system uses
the well-known level sensors. This send the
information about the vehicle level to the control
unit for headlight range control J431 via a pulse
width-modulated signal.
The same level sensor is fitted on both the front and
rear axle.
Headlights are also available with dynamic
corner-sensitive lights.
326_088
326_124