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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
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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
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
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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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– 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
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– CAN Communication:
The control unit is a participant on
CAN Convenience. Data exchange between all
the components of the access and start
authorisation system is performed via the
control unit.
It is also the diagnosis interface for the
components involved. All data, e.g. code,
immobiliser data, etc. is stored in the control unit
for access and start authorisation.
– Reading in the P/N signal from the control unit
for automatic transmission J217:
The signal is used to activate the displays
relating to engine start in dash panel insert J285.
Convenience electrics
326_062326_063
SELECT
N OR P
TO START
THE ENGINE SELECT
N OR P
START THE
ENGINE
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Vehicl e ke y
The key has a mechanically coded hinged bit for the
lock cylinder in the driver’s door and the tailgate/
boot lid. The transponder function is integrated into
the electronics and also works without a battery.
An integrated battery powers the electronics for the
radio remote control and Advanced Key functions.
A new feature here is the bi-directional data
exchange between the radio-control key and the
control unit for access and start authorisation via
the antenna for central locking and anti-theft
warning system R47. This is used to transfer the
status of the central locking system into the key.
If a button outside of the function range of the key
is pressed, the LED integrated in the key shows the
lock status of the vehicle. The lock status displayed
is always the status, which was achieved using this
key when central locking was last actuated.
If the vehicle is opened or locked in the interim
period using a second key, this does not change the
lock status in the first key.
Furthermore, the radio frequency is changed from
433 MHz to 868 MHz for the first time in many
countries. This radio frequency is ideal for data
communication between vehicle keys and the
control unit.
Since this frequency can only be used for very short
transmission pulses, any interference from
long-term radio transmitters, such as baby phones,
wireless headsets, etc. is eliminated.
326_138
326_058 Vehicle within key range
Vehicle outside of key range,
last vehicle status is locked Signals from the key LED
Vehicle outside of key range,
last vehicle status is not locked
Approx. 4 seconds on
off
on
off
on
off
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System overview
Convenience electrics
– Hall sender 1 for vertical adjustment of the
steering column
– Hall sender 2 for axial adjustment of the
steering column
– Bonnet switch for anti-theft warning system–Rotary light switch
–Hazard warning button
– Switch for reversing light (manual transmission)
– Sensor for rain and light detection (via LIN bus)
– Front direction indicator lights, left and right
– Side direction indicator lights, left and right
– Front parking light, left and right
– Dipped beam headlight, left and right
– High beam headlight, left and right
– Fog lights, left and right
– Relay for headlight cleaning system
– Windscreen washer pump
– Control unit for wiper motor (via LIN bus)– Supply, terminal 58
– Front footwell lights, left and right
– Relay for dual-pitch horn
– Steering column adjustment (vertical/axial)
– Selector lever lighting
– Indicator light for hazard warning lights
– Magnets for cover adjustment
Headlights (left and right)
326_110
The control unit for on-board power supply J519 evaluates the following input signals:
The control unit for on-board power supply J519 controls the following loads: