ALDL on V6 Cavalier

[Barry Tisdale]

If you can receive the 'chatter' - aka heartbeat - at least you know your
electrical hookup is ok and working.  I don't use EFIlive anymore to
directly read the ALDL, but once upon a time, I did.  The request frame to
be sent for the 749 is F0 56 01 B9; send within 3-5ms of receiving the
heartbeat and you'll get a 71 byte stream of data from the ECM; first 4
bytes are MAX echo of request, next is F0 95 01, then 63 data bytes, then
checksum.  Mode 0 request not needed here.  If your MAX232 (or other)
interface circuit echoes requests, indicate so to EFIlive.  I originally
ran a l-o-n-g serial cable from the vehicle to my PC, garage to office.

I agree that EFI is one complex prog, but being so full featured and
universal, that's unavoidable.  I *do* believe that its the hands-down best
prog available anywhere, though.  Sixteen simultaneous graphs of data is
unbeatable!

No financial interest, etc, but I put a *ton* of time in on it a couple of
years ago getting it to work w/ the SyTy 749.

Barry - Sy#26

At 02:07 AM 9/19/01 +0000, Eric S wrote:
>Well, I was able to recieve chatter from the ECM, I think I got the timing 
>right, I guess I just don't have the background.  I am pretty new to this 
>ECM stuff, I do some simple modifications on my own code for my car, so I 
>have a pretty good idea at what goes on.
>
>EFI live is just as confusing to me as hell right now, 
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