2002 C5 Which Custom OS?

[VortechC5]

I just want to make sure that I understand some aspects of the Custom OS for my 2002 C5 so that I can do this once and do it right. This leads to questions:

- My car is running stock OS 12221588. Can I or should I use the custom OS for 12593358 or should I use the one for 12221588? Will my .tun file saved from 12221588 upload/function ok if I use a custom OS for 12593358? I am asking because I thought that I read somewhere that 12593358 is a replacement for 12221588.

- I know that all of the custom OSes support MAFless. Do they also supprt running with the MAF?

- Just to double check...will my current PE based boost enrichment function in the custom OS version 03 exactly as it does now with my stock OS until I fit the 2 bar later?

Thanks.

[dfe1]

I just want to make sure that I understand some aspects of the Custom OS for my 2002 C5 so that I can do this once and do it right.
Forget trying to do it once. Even if you do it right, you'll do it more than once.


I thought that I read somewhere that 12593358 is a replacement for 12221588.
That's correct. I have a 2001 and when it came back from the dealer after the steering column lock recall, the operating system had been changed from 12221588 to 12593358.


I know that all of the custom OSes support MAFless. Do they also supprt running with the MAF?


They will run with or without MAF. I'm experimenting with two different tun files in my 01-- one is with MAF, the other is without. Both run very well and cause no problems, although it takes a bit more work to get the MAFless tune dialed in.


will my current PE based boost enrichment function in the custom OS version 03 exactly as it does now with my stock OS until I fit the 2 bar later?

It should. The custom OS is essentially a stock OS modified to enable certain tuning functions. Think of it as a "new and improved" operating system that does everything a stock OS does, plus a lot more. A custom OS doesn't do anything per se-- it ALLOWS you to do things that a stock OS doesn't. A custom OS is a tool and what it does depends on how you use it.

[VortechC5]

Thanks that helps a bunch. I'll probably go ahead and convert to a custom OS next week.

[lplott]

dfe1, Mark, GPMX, Blacky,

I have re-read all the posts on Custom OS and installation, and can not find where it says that Custom OS 12593358 is a replacement for 12221588.

If anyone know where this information is at or can tell me the difference in the two OS's and why one should be used over the other, please chim in as I am a little confused right now. (normal state between ears :roll: )

(Mark) Who did you have weld the WB02 bung in for you? Long weekend 7-10 Oct and probably will make the conversion/tune then.

Lonnie

[VortechC5]

Lonnie,

RMCR on Wanoka welded the bung in my header for me.

Mark

[Blacky]

I have re-read all the posts on Custom OS and installation, and can not find where it says that Custom OS 12593358 is a replacement for 12221588.

It is a replacement, but it's a GM replacement not an EFILive replacement.
Look in the Custom OS tutorial document on page 4.
You'll see:

GM OS EFILive OS Calibration file(*.cal) Tuning File (*.tun)
2002
12221588 020300xx 0203000x.cal 0203000x.tun
12593358 020400xx 0204000x.cal 0204000x.tun
That means:
if your stock GM OS is 12221588, then you can upgrade to one of EFILive's custom operating systems numbered: 020300xx.
if your stock GM OS is 12593358, then you can upgrade to one of EFILive's custom operating systems numbered: 020400xx.
Where xx is the version number. See page 3 for a description of the different version numbers.

In the table on page 4, you can reflash calibrations between operating systems on the same horizontal line, but NOT between operating systems on different lines.

If you have your PCM upgraded from 12221588 to 12593358 at a dealer you will lose all your calibrations and the PCM will be returned to stock. You will NOT be able to reflash your saved calibrations (from 12221588) into the new operating system (12593358) in your PCM - you'll have to copy all the values using copy/paste.

That means if you have put a lot of blood sweat and tears into tuning your current operating system, it is probably best not to get the dealer to upgrade your PCM - just upgrade directly to EFILive's custom OS 020300xx.

If you have not got much time/effort invested in tuning your current operating system, and you want to get the dealer update, then do so and then upgrade to EFILive's custom OS 020400xx.

I hope that helps to explain what your options are.

Regards
Paul

[lplott]

Thanks Paul. I thought we had to stay on the same horizontal line.

And I have NO intention of letting the dealer EVER reflash my PCM.

Lonnie

[VortechC5]

Thanks Blacky. That is exactly what we needed to know.