Odp: Motronic 2.4 (BMW motorcycles)

[Marek Skrzypiec]

Hi
Bosch usually use their own transmision protocol , which is accorded with
standart ISO 9141-1.
Usually transmision is bidirectional via line named -K , but sometimes are
used two lines :
1)bidirectional K for transmiting datas
2)unidirectional L only for begining .
In this case I think that it is one wire transmision.
To begin the protocol you must send byte $10 to ECM with baud rate
5baud(1start,7data,1oddparity,1stop).
After that you should recive six bytes , with  value $55 at begining - baud
rate is 4800baud(1start,7data,1oddparity,1stop but for first byte $55
:1start,7data,1parity,1stop).
Characteristic of ISO code is :
1byte - synchronization -always $55
2,3byte - family of ECM
4,5byte - key word
6byte -check sum.
When you will send !3byte (inverted) .At now transmision perform block by
block  with baud rate 4800baud(1s,8d,1s).Characteristic of block is :
1byte-dimension 31 bytes
2byte-title
0<byte<29-informations
1byte-check sum.
I wish you succesful
Marek

-----WiadomoϾ oryginalna-----
Od: Nils Powell <bini at tassie.net.au>
Do: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Data: 7 listopada 1999 03:32
Temat: Motronic 2.4 (BMW motorcycles)


>Greetings
>
>Is there anyone on the list who can assist please.
>
>BMW on the latest bikes use a Mot 2.4 system. They claim the diagnostic
>codes can only be accessed via their own MoDiTeC unit.
>
>A group of us have been trying to do this with normal workshop equipment
>but we cannot prompt a reply with any of the more common methods and a
>scope on the single diagnostics pin relevant to the Mot remains silent
>despite our efforts. We have tried grounding the pin and various pulses
>etc. At rest and O/C the pin has 12V and had a pull up resistor of some
>large value in series. There is no voltage drop across a 1K.
>
>We succeeded with the earlier 2.1 system and ABS 1 & 2 ( ie the 3 pin
>diag plug ) and if anyone could use this let me know. With these it is a
>simple procedure.
>
>For information the diagnostics plug is  round with 10 pins. 1 = Mot
>diagnosis   2 = ABS Diag  3= fuel reserve ( I think to set the low fuel
>warning light activation point )  4 = gnd  5 = trip computer (
>presumably for setting the output eg MPG or Lt per 100 Km ) 6 = B+  7 =
>Cruise control diag   8 =Radio Diag   9 = D+ ( Alternator output ) 10 =
>ti signal ( attached to the injector pulse line between injectors and
>ECU ) There is an 800 ohm resistor across the trip computer ( 5 ) to gnd
>( 4 ) when the diagnostic pin plug cover is in place.
>
>Is anyone with the right experience able to point us in the right
>direction so we can work at accessing  the diagnosis function ?
>
>Thanks and cheers
>Nils
>Tasmania. Australia.
>
>