GM vs CVN, any other way they would know?

[mirage2991]

I've seen the reply by Chris with the CVN number. I understand what it does and how it cannot change unless there's a modification in the parameters of the tune.
None the less I'm hearing rumors from famous shops that GM now has a way to find out if the ECM has "ever" received a tune, even if the ECM was then reflash with the stock GM tune.

If I could get some feedback from the pros about this "rumor" that would be great. (although I think those shops were talking about the CVN...but I could be wrong)

thanks!

[RWTD]

Unfortunately, as many times as we try to put this to rest, it keeps coming up. It's not your fault, however. It's just the individuals like you mentioned that love to stir up e-Drama.

[BBA]

You know, if you read the tune file checksum stock, then adjust parameters in the tune enough experimentally, you can get the same checksum on the tuned file and the CVN will read the same as stock.

One company even sells a 'stealth tune' that has been massaged this way.

Personally, I think if you tune and blow your shit up, you are on the hook for the repair, not GM, while I do think GM should not void warranty on a car if someone with a tune has problems not caused by the tune (such as lifters that are bad, etc...)

[mirage2991]

^ I have no problem with that.
I needed to ask because all I want to do right now is take off the CGAS, and bring up the idle a tad bit ( I like 750). None of that would be a cause for engine damage, I would just hate to have the warranty yanked over that...but, since Chris said that as long as you put the original stock tune of the car, there's no way they could tell, I'm ok with that...
The rumor mill sometime gets around...

[Penguin]

Buddy at GM sent me the latest TSB on this. If an engine or tranny has a mechanical failure, GM now requires a photograph of tech II screen showing calibrations sent to a specific office for confirmation and approval before they will authorize a warranty replacement. I was going to post the TSB but its too big for the board, if you want a copy pm me and get me your e-mail address and I would be glad to send it to you.

Personally, I think if you want to play that is the price you pay. Besides if you blow up an engine then you have an excuse for a bigger one!!

[Sneakyws6]

Suppossedly when the new replacement system for the Tech II comes out that is when they are going to be able to tell if the stock ECM has been flashed or not.

[EC_Tune]

But what if it wasn't flashed by Mr. Dealership but by someone else to the "latest & greatest" calibration. Unless there is an actual flash counter in memory and they feel like looking at it, they won't be able to tell that you flashed back to stock.

A flash counter could be quite meaningless anyway: For instance, a Tech (dealership or independent) decides to "update" your calibration to "fix" a problem that wasn't necessarily calibration related but that didn't fix the problem. Well now the flash counter increased for no "apparent" reason. What if it was done multiple times to "fix" the same problem. GM would have no record of that PCM being flashed by an independent shop.

[Cantalope Kid]

I swear...RWTD has said it before... BUY A REPLACEMENT PCM cry babies! Tune on the replacement and swap in the stocker when you go to the stealership! F*'in done son.

[mirage2991]

^ I like that idea!

[BoostedGTA]

I swear...RWTD has said it before... BUY A REPLACEMENT PCM cry babies! Tune on the replacement and swap in the stocker when you go to the stealership! F*'in done son.

Getting ready to purchase a replacement PCM for my 08 Corvette Z06. Anything I need to know to get it to work? I read something about a procedure you have to do for the security key or something...