Audi A5 - Page 40

40
Convenience system central control unit
Writing of data to an ignition key
There are three events which initiate a new write cycle on the ignition key:
1 when setting off on the first trip of the day
(but not until 40 seconds have elapsed after starting the engine and after exceeding a road speed of 20 kph)
2 after every 20 kilometres driven on the same day
3 after modification of the status information stored on the key.
(if, for example, a fault is detected in the headlight range control system)
On vehicles without the optional "Advanced Key", the writing of the "Audi Service Key" is implemented techni-
cally as follows:
393_011
Electronic
ignition lock module
E415
Extended-CAN
Convenience
control unit
J393
Data bus
diagnostic
interface
J533
Dash panel
insert
J285
Convenience CAN bus
Powertrain CAN bus
Dash panel insert
suspension CAN bus
LIN
The data for writing to the key is provided by the con-
trol unit with display in dash panel insert J285. Data is
transferred to the convenience system control unit
J393 via the dash panel insert/suspension CAN bus,
the data bus diagnostic interface J533 and the con-
venience CAN bus.
Note
Use is made of the same coil as for transferring the
immobiliser data.
The convenience system control unit transfers the data
via a LIN bus line to the electronic ignition lock module
E415, which transmits the data wirelessly to the igni-
tion key by means of a coil in the ignition lock. Here the
data is saved to an electronic chip.