View Full Version : Hey Ross! COS Tutorial

February 3rd, 2006, 03:27 AM
In regards to the Custom OS Upgrade tutorial. When upgrading from a '99, '00 to '01, '02 OS, custom or not, it might be a good idea to add and or emphasize the importance of manually transfering as much of the old tune into the new tune as possible.

February 5th, 2006, 12:20 AM
Yeah true, I just find it hard to think like a first timer all the time!.


April 23rd, 2006, 10:33 AM

I am working on this right now and I noticed that when upgrading from a 99 OS to a 01 OS on my 99 Silverado - I noticed a few odd things.

Orginal 99 OS 09379910 CAL 09379910


Stock 01 OS 12208322 CAL 12208511 (stepping stone for Custom OS)

{B5591,B5907} chart headings are linked to different PIDS

Went from KPA (range of 20 to 100) SAE.KPA to Grams/Cylinder {link GM.DYNCYLAIR_DMA} Range from 0.80 to 1.20)

Yet the actual chart data is exactly the same between the two tunes.

{B5910} The columnar data is inverted. The ECT values are the rows in the original 99 OS while the ECT is the columns in the 01 OS.

{B5919} The columnar data is inverted. The RPM values are the columns in the original 99 OS while the ECT is the rows in the 01 OS. You can't cut and paste when they are inverted. Not a big deal, just wondering why??

I believe there was one more in the trans specs, but I can't find it right now.

I am assuming the the new OS requires the data in that format, and I have left it alone, other than a few minor adjustments.

Since the orignal intent of this was to work my way to a custom OS, I thought a good practice would be to transfer over the important settings into the new tune, load it into my truck and start to shake down the 01 OS to make sure that it is happy running the stock 01 OS in my 99 before jumping up to COS and AUTOVE. Hence noticing the mismach when doing a few cut and paste operations.

Another question that does come to mind is that since I am flashing in new OS, how much of a risk if any is there that the newer OS will not play nicely with the other things that it controls such as the ABS system? :nixweiss: Is this a non-issue?

Please advise if I am missing something here.

Thanks in advance,


April 28th, 2006, 01:37 AM

You can't really transfer much from the older O.S's to the later ones.
GM did some fairly large table changes between those years. Generally people using the older O.S's will update to a 2001+ and disregard the old data because as you saw many tables are different for the same function.
If you Email me your VIN I should be able to track down a 2001 file for you to start working with.

You should be O.K with the later O.S, one of the truck guys might have a better idea there.


April 29th, 2006, 04:27 PM
Thanks Ross

Email sent...