Odp: Motronic 2.4 (BMW motorcycles)

[Nils Powell]

Marek Skrzypiec wrote:
> 
> 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

G'day Marek

Thanks for the reply. Unfortunatly whilst I have a good practical
knowledgeof EFI, I do not have your expertise with digital systems or of
programming. With this in mind could you spare the time to explain in a
little more detail the steps you described - keeping it as simple as
possible please.

I agree it is a single line bi-directional transfer of data but in
practice what do we have to do to get the codes.

Hope you can help

Cheers
Nils