GM 2.8L V6 ALDL

Shawn R. Lin slin01 at mail.orion.org
Fri Sep 15 19:50:30 GMT 2000


Barry Tisdale wrote:
> 
> This thread concerns the 749 ECU, correct?  From working w/ the SyTy box,
> the ECU needs to see F0 56 01 B9 in from 2ms to 5ms after the F0 55 BB
> 'chatter'.  Getting this timing right is what's giving Paul B a hard time
> getting EFIlive to read the 749s consistantly.

It's a 7727, but I think you're right, the timing is VERY important.  I
do have the F0 55 BB in the chatter as well.  If I send F0 56 01 B9
repeatedly, maybe the 9th or 20th time the DIC will say "DIAGNOSTIC
MODE".  However, that only lasts for a split second or so.  Once the ECM
is in Mode 1, does it stay in Mode 1 until a command is sent to switch
back to Mode 0, or do I have to send F0 56 01 B9 every time I want to
get a Mode 1 string returned?

> I've got a DOS based data grabber & display which works w/ EFI as a viewer
> (graphic) for the logged data.  Free for the asking.

Does it work with the 7727?
Thanks.

Shawn



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