Audi A5 - Page 22

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Convenience system central control unit
To ensure as straightforward a transition as possible from the three discrete control units J393, J518 and J723
to the "new" convenience system control unit, the different diagnostic addresses - 46 and 05 - have been
retained. The aerial reader unit for entry authorisation for keyless entry system J723 was also accessible pre-
viously for diagnostics via address word 05. This control unit was a LIN bus system user whose master was
entry and start authorisation control unit J518.
This means that
– data blocks
– adaption
– actuator diagnostics
– fault memory entries
and
– the Guided Fault Finding programs,
which belonged to the "old" convenience system control unit J393, can also be found in the "new" conven-
ience system control unit under address word 46.
The entry and start authorisation control unit and the aerial reader unit for entry authorisation for keyless
entry systems J723 are still accessible for diagnostics under address word 05, although control units J519
and J723 no longer exist as separate control units.
Diagnostic addresses
The convenience system central control unit is available in a number of different versions. These versions dif-
fer from one another in the following respects:
• the frequency of the remote control key (315MHz, 433MHz or 868MHz)
• installation of an anti-theft alarm system - "yes" or "no"
• the vehicle has "Advanced Key" - "yes" or "no"
• installation of an electric rear window roller blind - "yes" or "no"
However, all control unit versions use the same software and have the same basic circuit board. The versions
have different codings and different basic circuit board configurations.
Versions
Tasks of the convenience system central control unit J393
• Electrical steering column lock ELV
– Communication with the ELV control unit via LIN bus
– Output of locking enable signal via discrete line
– Reading in the "terminal 15" enable signal from the ELV
• Electronic ignition lock EZS and associated functions
– Communication with the EZS via LIN bus
– Reading in the microswitch in the EZS
– Activating the ignition key removal lock
– Terminals management