[Diy_efi] J1850 PWM Info Request

[Rick Richard]

I don't understand what the deal is.  I asked, I did not demand.
I thought the purpose of a mailing list like this was to share information 
and resources.  Perhaps you think it is presumptious of me to assume that 
someone here has this information?  I don't think so, because I've read 
archives of this list where people mention owning the SAE book with the 
protocol information in it.

I don't understand the relevance of "having a real job."  If you have the 
book, but don't have the time to share the info from it, then I understand.  
If someone has this info and is willing to share it, however, I'd rather do 
it that way than needlessly spend $80+ on a book that I would rather not 
buy.

All I want to do is make an open source PIC program to convert the J1850 PWM 
to a serial interface for use with one of the many scantool software 
packages out there.  VPW Is very well documented but few people seem to care 
about the ford PWM and the DIY kits that are out there for it are 
closed-source.



From: Mike <erazmus at iinet.net.au>
>Reply-To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
>To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
>Subject: Re: [Diy_efi] J1850 PWM Info Request
>Date: Mon, 10 Feb 2003 12:49:45
>
>Presumptive, or mildy impertinent I would have thought ;-)
>
>We aint a free library service, some of us have real jobs where
>people pay $200 an hour (on those rare occasions :)
>
>rgds
>
>mike
>
>
>At 08:42 PM 9/2/2003 -0800, you wrote:
> >Rick,
> >
> >Your approach at asking for information is a *little* coarse.  I don't 
>have
> >any of the SAE books, but I can recommend a good book that has all of the
> >Ford diag codes listed and a little bit of info.
> >
> >My suggestions are these:
> >
> >Get "Ford Tuning" by Ivan J. Kotzig.  He's the founder of Diablosport.  
>The
> >book is a little lite on tech stuff, but it does have little bits of 
>jewels.
> >On page 108 they describe some of the logical protocol used for the PWM.
>They
> >also describe the PWM encoding itself.  This is a good starting point and
> >reference.
> >
> >My next suggestion is to by an AutoXray and tap into the Data+ line for
>the PWM.
> >Use a logic analyzer or a circuit of your own design to sniff the data 
>off
> >the bus.  You should be able to get a fairly complete working example 
>using
> >this method.
> >
> >The rest is up to you.  There is a Yahoo group for an open OBDII comm
>interface,
> >but it implements the SAE proto and not the PWM.
> >
> >--Perry
> >
> >On Sun, Feb 09, 2003 at 07:42:58PM -0800, Rick Richard wrote:
> >> I know someone on this list as either the SAE J1850 standard or the SAE
> >> HS-3000 book.  I'd like to implement the J1850 PWM protocol that Ford
>uses,
> >> but I can't find the protocol specs online, the books are expensive, 
>and
>the
> >> custom chips are closed-source.
> >>
> >> Would someone scan the info out of their book(s) and email them to me?
> >> It would be greatly appreciated!
> >> -Rick
> >
> >--
> >Perry Harrington			Data Acquisition & Instrumentation, Inc
> >perry at dainst dot com					 http://www.dainst.com/
> >
> >Those who would give up essential liberty to purchase a little temporary
>safety
> >deserve neither liberty or safety. Nor, are they likely to end up with
>either.
> >                             -- Benjamin Franklin
> >
> >_______________________________________________
> >Diy_efi mailing list
> >Diy_efi at diy-efi.org
> >http://www.diy-efi.org/mailman/listinfo/diy_efi
> >
> >
>
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