Roca La Caca

I-BUS Inside
Inside the BMW Cars entertainement Serial Bus

Written by Franck Touanen.
HackIBus@Yahoo.fr

2002, December.
Version DRAFT. REV 5.

Introduction and warning................................................................................ 4
Bus in automotive applications....................................................................... 5
I-Bus GeneralArchitecture............................................................................. 7
I-Bus Messages.............................................................................................. 8
Typicals Device IDs ................................................................................. 8
I-Bus Packet Structure............................................................................. 9Hardware to read/write I-BUS ...................................................................... 10
Basic Interface....................................................................................... 10
Contention Detection Interface .............................................................. 11
Melexis Chip Interface........................................................................... 11
I-BUS Analyser software .............................................................................. 12
The I-Bus Analyser Software. (V1.00) .................................................. 12
Steering Wheel Messages ........................................................................... 17
Messages to Radio(68H)..................................................................... 17
Messages to Telephone (C8H).............................................................. 17
Instrument Control Messages (IKE)............................................................. 18
Messages to OBC Text (E7H)............................................................... 18
Board Monitor Buttons (Nav system) ........................................................... 20Messages to Radio (68H)..................................................................... 20
Messages to Navigation / Video (3BH).................................................. 21
Broadcast Messages (FFH)................................................................... 21
RADIO Messages ........................................................................................ 22
Messages toNavigation / Video (3BH).................................................. 22
Messages to Instrument Control Electronics – IKE (80H)..................... 25
Messages to CD Player (18H)............................................................... 25
I-BUS INSIDE

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CD PLAYER Messages ............................................................................... 27
CD Player behaviour............................................................................. 27
Broadcast Messages (FFH)................................................................... 27
Messages to Radio (68H)...................................................................... 27
Navigation / Vidéo module Messages.......................................................... 28
Messages to IKE (80H)......................................................................... 28

I-BUS INSIDE

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Introduction and warning
A part of this information is based on research done by Thomas L. Wood, who has connected a Linux
embedded PC in his E39 (without NAV) to play MP3 . After exchanges with Thomas, I built my own interface
to start I-Bus analysis with the objective to interface a MP3 pic basedplayer fully integrated with the board
monitor.
Note that all this document is based on analysis done in a E39 (July 2000) with a MK II navigation system.
I can't ensure if informations and/or device behaviours are identical for others models.
DISCLAIMER :
I'm not related in any way with BMW AG or any of its subsidiaries. All trademarks are property of their
respective owners. Any copyrighted...