audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
MMI basic/basic plus Navigation - overview > < General notes (up to week 44/08)

A4 Mk3

General notes (from week 45/08 onwards)
General notes (from week 45/08 onwards)
The MMI fitted from week 45/08 onwards is an enhanced version of the MMI which has been used up to now. The functions for control unit, telephone, mobile phone pre-installation, connection for external audio sources, CD and DVD drives, navigation system (with hard disk) and speech dialogue system are all integrated in the control unit 1 for information electronics -J794- as one unit.
The radio -R-, CD changer -R41-, TV tuner -R78- and digital sound package control unit -J525- are externally linked to the system via the MOST bus. The basic sound systems are directly activated by the radio -R-. The optional digital radio -R147- (DAB) is integrated in the radio -R-.
The following versions of the MMI infotainment system are available:
MMI minimum equipment
t  Control unit 1 for information electronics -J794- in dash panel contains CD player / SD memory card readers
t  Multimedia system operating unit -E380- in centre console
t  Display unit for front information display and operating unit control unit -J685- in dash panel (centre)
t  CD changer -R41- / optional connection for external audio sources -R199- (interface) in glove box
t  Connection for external audio sources -R199- (AUX IN socket) in centre console storage compartment
t  Optional digital sound package control unit -J525- in luggage compartment (rear left)
t  Sound system: basic/basic plus/standard/Bang & Olufsen
t  Radio -R- in luggage compartment (rear left)
t  Mobile phone pre-installation (fitted optionally)
t  Multi-function steering wheel (fitted optionally)
MMI maximum equipment
t  Control unit 1 for information electronics -J794- in dash panel contains CD player / DVD player / navigation system / Bluetooth car phone / voice control system / SD memory card reader
t  Internal hard disk (HD) to store navigation data and MP3 files
t  Multimedia system operating unit -E380- in centre console
t  Display unit for front information display and operating unit control unit -J685- in dash panel (centre)
t  CD changer -R41- / optional connection for external audio sources -R199- (interface) in glove box
t  Connection for external audio sources -R199- (AUX IN socket) in centre console storage compartment
t  Digital sound package control unit -J525- located in luggage compartment (rear left)
t  Sound system: Standard/Bang & Olufsen
t  Radio -R- in luggage compartment (rear left)
t  TV tuner -R78- in luggage compartment (rear left)
t  Mobile phone pre-installation (fitted optionally)
t  Multi-function steering wheel (fitted optionally)
t  WLAN (WiFi) - from model year 2013 onwards
The exchange of data in the MMI systems takes place via the MOST bus.
The connection to other data bus systems in the vehicle is handled by the data bus diagnostic interface -J533-.
Fault finding is performed via the „Guided Fault Finding“ → Vehicle diagnostic tester.
For more information, refer to → No.286.
Control unit 1 for information electronics -J794- - layout
The control unit 1 for information electronics -J794- is a third-generation MMI version. Depending on the equipment version, the control unit 1 for information electronics -J794- contains the following control units known from the second generation:
   
1 - Control unit for front display and information control panel -J523-
2 - CD player -R89-
3 - Navigation system with CD drive control unit -J401-
4 - Chip card reader for telephone -R115- / SD card reader
5 - Speech input control unit -J507-
6 - Telephone transmitter and receiver unit -R36- (Bluetooth car phone)
7 - Telephone transmitter and receiver unit -R36- (phone pre-installation)
8 - Internal hard drive (HD)
9 - Control unit 1 for information electronics -J794-

Radio -R- - layout
Depending on the equipment version, the radio -R- contains the following control units known from the second generation:
   
1 - Digital sound package control unit -J525-
2 - Radio -R-
3 - Radio -R- (AM/FM tuner)
4 - Satellite radio -R146- (USA only)
5 - Digital radio -R147- (Europe only)

MOST bus - layout
   
1 - Display unit for front information display and operating unit control unit -J685-
2 - Control unit 1 for information electronics -J794-
3 - MOST bus
4 - CD changer -R41-
5 - TV tuner -R78-
6 - Radio -R-
7 - Digital sound package control unit -J525-
8 - Data bus diagnostic interface -J533-
9 - Multimedia system operating unit -E380-

Notes on MOST bus
In addition to the CAN bus, the fibre optic data bus „MOST bus“ is used.
A „fibre optic cable“ is used as the connecting cable. The fibre optic cables are fitted in corrugated tubes for protection.
Renew the complete fibre optic cable whenever possible.
It is important to ensure that the end faces of the connectors do not become dirty.
   
If connectors are unplugged: fit a protective cap for cable connector -VAS 6223/9-.
When installing the fibre optic cables, be sure to observe the minimum bending radius of 25 mm. Do not crush or kink the fibre optic cable.
Repairing fibre optic cables → Electrical system; Rep. gr.97.
For more information, refer to → No.286.
  W00-10202

MMI basic/basic plus Navigation - overview > < General notes (up to week 44/08)