GM 2.8L V6 ALDL

[Scot Sealander]

"Shawn R. Lin" wrote:

> Actually, I found out Carbytes is calculating the checksums correctly,
> but is changing the string!

Maybe correcting the string?


> The problem now seems that Carbytes won't send a $58!
> CarBytes automatically changes $F0 $58 $01 to $F0 $56 $01 $B9.
> What's up with that???

Well, he is making the byte count right.  The first byte is MessId.
The second byte is the count.  The 3rd byte is the mode. The fourth
byte (in this case) is the checksum.  CarBytes is correcting the byte
count.

The byte count is wrong in the example I gave you.  I'm sorry, I did not
even look at it for correctness, only checksum.  So the F0 56 01 B9 is
correct.  If the ECM does not respond, then something is wrong.  You
do have to transmit at the corrrect time, when the ECM is listening.
I don't think carbytes watches the chatter and then transmits at
the correct time.  May make it hard to get in.

The program I sent you listens and transmits at the right time.  It will
read memory Ok, but it will not send the scan tool string.  Maybe it is
time to debug that section....  Oh, and it needs a DOS machine.  ;-)

Scot Sealander
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