[Gmecm] Sunbird/$58 ALDL protocol

[Mark Mansur]

Hi Robin -

I've had much recent experience with $58 in my work to make TunerPro much 
more robust.

Indeed $58 is rather chatty and timing sensitive. The ECM/BCC send "I'm 
alive" chatter message ($F0 $55 $BB) every 200ms (if I remember correctly). 
In order to get that to stop, you need to listen for the chatter message and 
respond with a MODE 1 dump request in the window between the chatter 
messages. Some docs seem to mention that you can send the message at any 
point between, but that doesn't seem to be the case. I send the mode 1 
request 1ms after I receive the $BB. Note that many other ECMs that function 
like this actually require a mode 8 command to silence chatter (and a Mode 0 
to restart normal comms), but $58 requires a mode 1 dump. If you get a 
successful reply from the mode 1 dump request, the ECM will be silent for as 
long as you continue to send requests to the ECM. If your requests cease for 
5 seconds, the chatter will once again begin.

What you describe does indeed sound like a bug in your test program (are you 
flushing the FIFO as you should be?).

More helpful information from Blacky can be found here:
http://www.diy-efi.org/gmecm/archive/html_gm_archive_num_12/msg08681.html

Hope this helps, and good luck!

Mark


----- Original Message ----- 
From: "Robin Handley" <Robin at FuryWorld.fsnet.co.uk>
To: <gmecm at diy-efi.org>
Sent: Sunday, June 04, 2006 9:26 AM
Subject: Re: [Gmecm] Sunbird/$58 ALDL protocol


Hey Bill,

I think you're dead right about the timing sensitivity. I'm really surprised
that GM made the $58 code behave differently from the $8D, though. My
current $58 test program waits until it sees the $BB checkum of the chatter
message and immediately after sends a request for Mode 1 data - which the
$58 responds to with data, and the chatter message is inhibited for a few
seconds. It seems that, if the Mode 1 request doesn't come out at just the
right time, it is ignored and the chatter messages just churn out. That
isn't the case with $8D. The weird thing is that, with my test program, the
$58 code gives me the Mode 1 data 3 times consecutively from my program
start and then ignores subsequent requests! If I stop and restart my program
it does the same again. This sounds like a bug in my program, but I tried
the program with ANHT/$8D and it worked fine! I know the $58 should work
repeatedly because, once locked on, ALDLMON works. This is really confusing
me ATM! :-)

BTW: Yes, the Turbo P4 doc is the one I was referring to. Following what it
describes, I've been testing the Mode 4 ability to turn the fan on, like I
did for ANHT/$8D, and having problems with that too, using $58! I expected
it to work straight away! :-(

BR,

Robin

----- Original Message -----
From: "Bill Shaw" <b.shaw at comcast.net>
To: <gmecm at diy-efi.org>
Sent: 04 June 2006 16:29
Subject: Re: [Gmecm] Sunbird/$58 ALDL protocol


> Hi Robin,
>
> The $58 code is very timing sensitive.  It's been a while since I've
played
> with it so the details are a bit fuzzy,  but as I remember you have to
send
> a mode change within a couple hundred milliseconds of the 'chatter' packet
> to get it to shut up and start taking commands.  Once you change mode
it'll
> respond OK to your commands until it times out aned returns to 'chatter'
> mode.  Do you have the Turbo-P4 doc?  It's spelled out pretty well in
there,
> look for 'turbo_p4' or something like that on incoming.
>
> Best,
>
> Bill
>
> > From: "Robin Handley" <Robin at FuryWorld.fsnet.co.uk>
> > Reply-To: gmecm at diy-efi.org
> > Date: Sun, 4 Jun 2006 15:45:12 +0100
> > To: <gmecm at diy-efi.org>
> > Subject: [Gmecm] Sunbird/$58 ALDL protocol
> >
> > I've noticed different behaviour on ALDL between ANHT/$8D and
Sunbird/$58
> > code in my '727. The ANHT/$8D seems to behave more
'sensibly/predictably.'
> > than the Sunbird/$58 code!
> >
> > I'm currently trying to find a robust algorithm to talk to the
Sunbird/$58
> > code. I have modified ALDLMON (which works but takes longer to lock on
than
> > it does with ANHT/$8D) and played around with some noddy programs of my
own
> > (not w/o some issues, which I'm still trying to get to the bottom of).
Has
> > anybody played with ALDL from Sunbird/$58? The code chucks out $F0 $55
$BB
> > repeatedly. The Turbo code doc. indicates that the ALDL monitor should
> > reply, but does not appear to say with what. Anybody know what the
correct
> > response is?
> >
> > Robin
> >
> > _______________________________________________
> > Gmecm mailing list
> > Gmecm at diy-efi.org
> > http://lists.diy-efi.org/mailman/listinfo/gmecm
>
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