Re: Any other GM comms speeds?

["alexpeper" <alexpeper@email.msn.com>]

If is obd-II as below I have software for the J1979 specs.
Also have ISO 9141 hardware interface if different Bosch
baud rate or keywords is needed, K line only.
Alex
----- Original Message -----
From: Andy Whittaker - Chester UK <arwefi@netcomuk.co.uk>
To: <gmecm@diy-efi.org>
Sent: Thursday, June 15, 2000 6:56 AM
Subject: Re: Any other GM comms speeds?


> I think, more specifically, it's ODB-II. What Malcolm is
describing sounds
> like the initial wake-up that OBD-II needs to initiate the
ISO protocol.
>
> A little taster:
>
> ISO does a wacky initialisation sequence:
> To ECU: 0x33 at 5 bps (This is "Address" NB with start and
stop, takes 2
> secs!)
> From ECU 0x55 at 10.4k ("Synchronization")
> From ECU 0x08 0x08 OR 0x94 0x94 at 10.4k ("Keywords")
> To ECU 1s complement of last "Keyword" (ie 0xF7 or 0x6B)
> From ECU 1s complement of "Address" (ie 0xCC)
> Address is transmitted on both K and L, all further
communication is on L
> only. If Keywords are 0x08 then gaps between messages are
minimum 25ms, if
> Keywords are 0x94, gaps can be 0.
>
> (Info from Nick Reilly).
>
> P.S. Hey Malcolm, did you ever fathom out the ALDL
protocol on the Lotus
> Carlton? I roughly disassembled the Lotus Carlton ECU code
from the .bin
> that was in the incoming directory of the EFI site. I
could now, probably
> set up a FreeScan conversation with the Carlton's ECU but
I have no
> DataStream information.
>
> Andy.
> ------------------------------------------
> Andy Whittaker
> Chester, England.
> Email: mail@andywhittaker.com
> Web: http://www.andywhittaker.com/
> ECU Stuff: http://www.andywhittaker.com/ecu/
>
> ----- Original Message -----
> From: "Malcolm Robb, LC 0112G"
<Webmaster@lotus-carlton.fsnet.co.uk>
> To: <gmecm@diy-efi.org>
> Sent: Thursday, June 15, 2000 10:22 AM
> Subject: RE: Any other GM comms speeds?
>
>
> > Yup - Most European Vauxhalls and Opels use Bosch
Motronic ECU's, and
> their
> > baud rate is 9600. Worse than that, they actually need
to receive a 5 (yes
> > five) baud 'enable' character before they will talk at
9600. All the ECU's
> > in the car (Engine ECU, alarm, gearbox, digital dash,
trip computer
> > etc,etc) are connected via the ALDL port, and the 5 baud
character is used
> > to select which device you want to 'talk' with
> >
> > The only European Vauxhall/Opels that I am aware of that
use the GMP4 are
> > the Lotus Carlton/Lotus Omega (the best car the world
has ever seen
> :- ) ),
> > and the Monteray 3.2 V6 (a Range Rover type thing). Both
of these use the
> > standard 8192 baud comms.
> >
> > I have the Vauxhall/Opel cartridge for the Tech1 scan
tool. If you can
> tell
> > me which car the ECU originally came out of I can have a
quick poke about
> > to see what the Tech1 tries to do to initiate comms.
> >
> > Another possibility is that the previous owner of the
ECU modified it so
> > that it could be used directly with a PC's COM port !?
> >
> > Cheers,
> > Malcolm Robb, LC 0112G
> >
> > -----Original Message-----
> > From: Ross Myers [SMTP:ponty@axis.jeack.com.au]
> > Sent: Wednesday, June 14, 2000 10:45 AM
> > To: GM ECM List
> > Subject: Any other GM comms speeds?
> >
> > Hi all,
> >
> > I've been playing around with a 16188269 ECU (Picture is
at my web page),
> > these are strange in that they have no Flash or Memcal,
it was built in
> > 1995. The CPU seems to match the HC11 'E' series so I
guess it may have
> 20K
> > or so of OTP.
> > Anyway, I'm want to dump the memory contents out via a
Mode2 request, only
> > I
> > cannot get this thing to talk to me!!, the wiring diag
shows a
> > Bi-directional Serial Data line on the ALDL, but no
matter what I.D byte I
> > use for a Mode1 request I get no response (I've tried
$01 - $FE).
> > First thing, the ECM has no 64606 I.C fitted, instead
the serial data runs
> > through transistor/resistor combinations to the CPU
Rx/Tx pins.
> > Secondly, this ECU is used in the U.K on Opel & Vaxhuall
cars as well.
> > So, did GM use another speed other than 8192 for
bi-directional comms?.
> >
> > Thanks,
> > Ross Myers
> > Melbourne, Australia
> > E-mail : ponty@axis.jeack.com.au
> > Stuff : www.jeack.com.au/~ponty
>
>
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