Audi A5 Service Training page 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:
Electronic
ignition lock module
E415
LIN
Convenience
control unit
J393
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.
40
Extended-CAN
Data bus
diagnostic
Convenience CAN bus
interface
J533
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.
Dash panel insert
Dash panel
suspension CAN bus
Powertrain CAN bus
insert
J285
393_011