[Gmecm] Sunbird/$58 ALDL protocol

[Robin Handley]

Thanks Mark. I've yet to find the bug (been fighting other ECM 'fires') but
I intend to find out what's going on...

Robin

----- Original Message -----
From: "Mark Mansur" <mmansur at hotmail.com>
To: <gmecm at diy-efi.org>
Sent: 04 June 2006 19:33
Subject: Re: [Gmecm] Sunbird/$58 ALDL protocol


> 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