Any other GM comms speeds?

[Malcolm Robb, LC 0112G]

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 at 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 at axis.jeack.com.au
Stuff : www.jeack.com.au/~ponty

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