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

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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

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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

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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

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326_147
1 Door control unit, driver's side J386
2 Control unit for on-board power supply J519
3 Control unit for access and start
authorisation J518
4 Switch for access and start authorisation E415
5 Central locking button for outer door handle,
driver's side E369
Outer door handle switch in driver’s door F272
Sensor for outer door handle contact,
driver’s side G415
6 Antenna read-in unit for keyless access
authorisation J723
7 Antenna on driver’s side for access
and start authorisation R134
8 Door control unit, rear left J388
9 Passenger compartment antenna 1 for
and start authorisation R138
10 Door control unit, passenger's side J38711 Central locking button for outer door handle,
rear left E371
Outer door handle switch, rear left F274
Sensor for outer door handle contact,
rear left G417
12 Central locking button for outer door handle,
passenger’s side E370
Outer door handle switch in passenger’s
door F273
Sensor for outer door handle contact,
passenger's side G416
13 Antenna on passenger’s side for access
and start authorisation R135
14 Door control unit, rear right J389
15 Antenna for central locking and
anti-theft warning system R47
16 Central locking button for outer door handle,
rear right E372
Outer door handle switch, rear right F275
Sensor for outer door handle contact, rear
right G418
17 Boot antenna for access
and start authorisation R137

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Division of functions
System control is broken down into three basic
modules:
– the control unit for access and
start authorisation J518,
– the antenna read-in unit for keyless access
authorisation J723 and
– the switch for access and
start authorisation E415.
All three components communicate with each other
over a local single-wire bus.
The control unit for access and start authorisation is
the master of the system and a participant on
Convenience. The same control unit is installed for
all system versions.
The antenna read-in unit for keyless access
authorisation is only installed with the
Advanced Key option. It serves as the interface
between the antennae, sensors and the control unit
for access and start authorisation.
The switch for access and start authorisation is
installed in various versions, depending on the
transmission, radio frequency of the central locking
system and the Advanced Key option. An evaluation
electronic device is also integrated into the switch.
Convenience electrics
326_064
Access and
start authorisation
J518Antenna read-in
unit for
keyless access
authorisation
J723
Switch for
access and start
authorisation
E415

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The control unit is only installed together with the
Advanced Key option.
It is located at the right of the dash panel, behind
the glove compartment.
It evaluates the signals from the outer door handle
sensors and then activates the antennae for access
and start authorisation.
The capacity-based operating sensors in the outer
door handle detect any contact on the handle and
send a signal shortly afterwards to the antenna
read-in unit for keyless access authorisation.
The antenna read-in unit evaluates the signal and
then sends a query to the vehicle key via the
antennae for access and start authorisation.
The sensors switch off after approx. 80 hours once
the vehicle is locked or after 20 actuations without
an authorised key.
Convenience electrics
326_097
Antenna read-in unit for keyless access authorisation J723
Sensors for outer door handle contact G415 - G418
326_096

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Opening the vehicle
Convenience electrics
326_055 Antenna for
central locking and
anti-theft warning
system
R47
Antenna on driver’s
side for access
start authorisation
R134Antenna on
passenger’s side for
access start
authorisation
R135Passeng er
compartment
antenna 1 for start
authorisation
R138
Boot antenna for
access
start authorisation
R137
Switch for
access and start
authorisation
E415
Antenna read-in
unit for keyless access
authorisation
J723 Control unit for
access and
start authorisation
J518
Door control unit,
driver’s side
J386
Central control unit
for
convenience system
J393Sensor for
outer door
handle contact,
driver’s side
G415

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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.

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Starting the vehicle using the button
Convenience electrics
326_056 Antenna for
central locking and
anti-theft warning
system
R47
Antenna on driver’s
side for access
start authorisation
R134Antenna on
passenger’s side for
access start
authorisation
R135Passenger
compartment
antenna 1 for access
and start
authorisation
R138
Boot antenna for
access
start authorisation
R137
Switch for access
and start
authorisation
E415
Antenna read-in
unit for keyless access
authorisation
J723 Control unit for access
and start authorisation
J518
Data bus diagnosis
for data bus
J533Engine control unit
J623 Button for access
and start
authorisation
J408

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1 The driver presses the button for access and
start authorisation E408 down fully. The button
sends the information about "Ignition on" and
"Engine start" both to the switch for access and
start authorisation E415 and to the control unit
for access and start authorisation J518.
2 The switch for access and start authorisation
passes the information from the button on to the
control unit for access and start authorisation via
the data lead. The two button information
messages are compared there.
3 The control unit J518 sends a key query to the
antenna read-in unit for keyless access
authorisation J723.
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 in the vehicle and sends its
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 switch for access and start authorisation
E415 passes the information on to the control
unit for access and start authorisation, which
then evaluates it. 6 Based on the key evaluation, the S contact is
sent to CAN Convenience and the steering is
unlocked.
7 As soon as the steering is fully unlocked,
terminal 15 is switched on.
8 Once terminal 15 has been switched on, data is
exchanged between the engine control unit and
the control unit for access and start
authorisation via the CAN bus. The immobiliser is
then deactivated.
9 The control unit for access and start
authorisation sends the "Start request" signal to
the engine control unit. The engine control unit
checks whether the clutch is depressed or
whether P or N is selected in the case of an
automatic gearbox and then performs the fully
automatic engine start.