Kilroy's 99 TA

I like playing around with shift points and such, can I use LS1Edit for the engine programming and still use HPP3 for other non-engine related things?

RPM WS6

iTrader: (3)

I had my PCM tuned by MTI which is now using LS edit. Jayson told me that I could try messing with the shift points with HPP3 if I really wanted to, but he said that he does not recommend using it with their tuning anymore. I would assume that this would apply to all LS1 edit tuning. I have not tried my HPP3 since I got the LS1 edit tuning.

Red 99 TX SS

Jayson told me the same thing. He didn't know if the HPP3 changes were compatible with the LS1Edit tuning.

02BlackWS6

Just my .02 here. But LS1 Edit is basically an interface with the binary data thats in the PCM. LS1 Edit doesn't encript that data. It just turns the binary data which is unreadable to TEXT information so we can see it and make changes to it. So yes, we can still use the HPP3 to adjust things. Unless LS1 Edit totally encripted the whole PCM data. Cause if they did that GM's TechII wouldn't be able to read the PCM's data. And that would be border line illegal. Because it would stop us from adjusting our own PCM. And make it impossible for a dealer ship to diagnose our cars if we had a problem.

[ January 04, 2002: Message edited by: 02BlackWS6 ]</p>

Camaroholic

iTrader: (1)

LOL Illegal? Nope.

Some tuners don't like to calculate checksums on the PCM program. It takes time. So, they set the 'checksum disable' flag, and do their business, and don't worry about the software checksum.

When an HPP encounters one of these PCMs, it programs it, but then it goes to verify that it programmed 'correctly', it notices the bad checksum, and it tries to program again (it does not look at the checksum disabled flag). It will continue to reprogram as long as it's plugged in to that car. The only way to fix it is to load a valid checksummed program in to that PCM and let the HPP finish. I've seen it myself when unlocking a 94-95 LT1 HPP.

Of course, it's possible for a tuner (who is sharp enough with the assembly code) to stick a few lines in there and make it impossible to read the PCM code out, or to set some bits and confuse an editor like LS1_Edit. There is nothing illegal about this either, and I do fully expect it to happen - in this case, the user of LS1_Edit will probably need to start over with a clean file for their vehicle.

LS1_Edit (I am making an assumption that it's similar to LT1_Edit) should automatically recalculate the checksum and store the proper value in the PCM. There *shouldn't* be a problem using the HPP with an LS1_Edited file, assuming the checksum portion is correct (which I know they do like to have that part correct).

-Andrew

MTI

LS1 Edit does verify the checksum before it programs the changes to the PCM. The only discrepencies I have seen are in the HPP3's themselves. Depending on when your HPP3 was made, some will add or subtract from the existing shift point number while others will substitute their own shift point mph #. Both work with the LS1 Edit modified PCM, however, the HPP3 that adds/subtracts is the only unit that will allow you to adjust the shift points correctly with the tuning installed. I do not know(yet) which programmers are which right now but I'll try and find out. Hope this clears things up a little.

Jayson - MTI <img src="gr_images/icons/wink.gif" border="0">

DanZ28

iTrader: (5)

My HPP3 works fine on my 2000 Z28 with LS1 edit. I'll just have to make sure I don't use the HPP3 engine tuning if it causes problems with the shift points.