Best factory OS for a P01 / 411 / 512kb PCM?
 

Like the subject line asks... What's the best factory OS for 411 PCMs?

Feel free to define "best" however you want.

But please don't suggest HPTuners or EFI Live stuff - those are out of scope for this thread. I'm on interested in GM's operating systems.

The reason I ask is that I want to start reverse engineering a 512kb OS, and eventually make some changes to it. I'd rather not invest a ton of hours into this only to find out that I should have started with some other OS because it's the one everybody else uses, because <insert great reason here>. It will most likely be possible to make changes to other OSes later, but only with a lot of extra work, so I'd like to keep that to a minimum.

If it matters, my car is drive-by-wire and manual transmission, so those are must-have for me.

As for the changes I want to make... I don't want to over-promise and honestly don't yet know where I'm going to start, so I'm going to stay vague about that. But I do have a few things in mind.

Thanks!

I thought most liked to upgrade to the factory 02 OS, 12212156.

12212156 is the best OS for a 896/411 pcm. Its a 2002 OS like ddnspider said.

Thanks guys. Is there any reason not to use 12593358 ? It's my understanding that this was an update that came out for cars that had 12212156 but I'm not really sure.

Edit... Just found a post on another forum saying that 12212156 is segment-swap compatible with the 512k OSes that came after it (including 12593358, so it might not really matter.

12212156 was the latest OS GM did for the 2002's. It's available in manual, 4l60 and 4l80 so its great for segment swaps for all of those trans.

I haven't been able to verify this authoritatively, but I've found a few posts on other forums that say pretty much the same thing:

The only information I have found from GM about that campaign says that it was for the steering column lock problem, but it also does say that a PCM reflash was part of the job.

My car is a 2002 C5Z, and the seller said he had the column lock service done, and the PCM has 12593358 on it.

Edit: It's not clear whether there's an automatic-transmission version of 12593358, so 2156 might be the best way to go.

afaik 2156 has the most features and support with HPT and tunerpro. It's really the only OS I use in swaps anymore.

gimme boost by gear plz

LOL! Maybe someone will, CLEARLY HPT will not.

OK fine, I'll think about it. :) But let's use a different thread for that:

https://ls1tech.com/forums/pcm-diagn...l#post20030014