01 1500HD tune file

I'm helping a friend out with a 01 1500HD he's working on in his shop.My main question is how important is it that all of the segments in the tune match? I put his VIN into TIS, and I cannot find a base file on the internet that matches his segments. The reason I'm looking for another tune file is his was modified with HPTUNERS, and it is doing some REALLY wierd shifts and were having problems with the fans working properly. So I want to start over with a clean slate to transfer his current custom tune over to, and the tune file on tunefile depot doesn't match the segments that TIS lists for his truck per the VIN. Or would I be that much better off to sit down and copy his custom tune over to an 02 OS and flash that in? He has a custom tune from a well known tuner now that he had me flash in, but we just can't get the trans to shift right into lockup consistently and I want to make sure there weren't changes made with HPtuners that I cannot see.

1500HD? Does that even exist? Thought the 2500s were the first in the HD lineup, 2500HD and 3500HD.

If its a gasser, its a 512kb LS1B PCM so LOTS of options. Just grab an 02 12212156 OS and full flash it. Heck TuneFileDepot has all the gas engine options covered so you can just pull the right motor size and start from there.

So no, all of the segments dont have to match up exactly. If you really want the latest and greatest, flash it with Tis2Web for an 12212156 OS from 02.

It's hit or miss, but early on and then later they offerred the 1500HD or the 2500 NON HD truck. Same truck, just different badging. It came with 3.73 gears in most of them, and a 9.5" semi floater rear instead of the 10.5" full floater the HD's got. Still 8 lug though. He already has a blackbear tune that I flashed in it, but the trans just doesn't act right as well as some other wierd issues with the electric fans and I want to make sure that it wasn't something from the tune that was done with HPTUNERS as blackbear used his tune file I read out of it to build off of.

Hmm interesting, I know about the 2500 non HD but didnt know there was a 1500HD! Thanks GM, another quirky thing. :)

Well you can pull the Blackbear tune and flash the 02 OS, if it works correctly then start copying the tables from the Blackbear tune over to the 02 OS.

I may give that a try. I know it will not run on a stock tune as this 6.0L is HEAVILY modified with a cam, heads, tunnel ram intake, 80MM throttle body, 65 lb/hr injectors, and a supercharger. And I did some digging and it looks like the 2500HD uses a completely different OS than the 1500HD does(same OS number, but that is where the simliarities end). Just makes this more fun to try and sort out his wierd shifts. I REALLY wish I could have gotten a read on it BEFORE he had it dyno'd tuned and screwed up by the previous shop.

Gotcha, maybe try the 5.3L OS as its for a 1500 and setup the cylinder volume and related tables to match the actual engine.