Chappy1062

I had previously been told by a dealership that my ECM was locked and was not able to be read. I hooked up a Diablo Trinity and it showed the following. Can anyone tell me if these are stock tunes and if I can read this is the ECM locked. Thanks

Mike@DiabloSport

Unfortunately the OS does not have to be changed for the PCM to be locked, thats in the seed/key routine.

What does the Trinity say when you try to let it read out the stock tune?
If it saves it, its not locked

Chappy1062

Thanks for the reply. I'll try it when I get home. From what is shown in the pictures would it appear that it has an aftermarket tune? If so, how can I tell? It seems to me all is stock because they all start with 126 XXX. I'm just guessing so please forgive my ignorance. Thanks again,

Chappy1062

"Trinity was unable to save your original tune after 2 attempts. This can happen if the vehicle already has a performance tune".... I concede it's locked. I'm back to the options previously provided. . Thanks again for your help.. I'll quit

Mike@DiabloSport

Yup, sounds locked to me.
One of the more info screens should have said something about error seed/key as well.

Chappy1062

Where would I look? I did not see any seed/key error. The fail described above was seen after trying to backup the existing tune.

tblu92

Even though a tune is locked it means that it CANNOT be read until unlocked with the proper password
However it still can be WRITTEN OVER with a "FULL FLASH" tune
To download a full flash having the VIN # and better yet the OS # will aid in getting the tune flashed to 100% back to original STOCK--
IF you can't get the OS #then you risk having some of the communication to the BCM not to be accurate----The BCM will control things like cruise control --fuel tank size-- door locks--radio etc--Nothing engine related---But after a full flash once you have a stock tune installed you can always try to correct the anomalies
On a Corvette the risk of having an incorrect OS is rare but like on a Silverado with so many options there are several OS's and the chance of getting it wrong is increased
A full tuner like HP OR EFILIVE can do a "Full Flash"

PS: Here where I live in Calif the dealer CAN do a full flash as well--Seems like all dealers can but maybe your's doesn't want to--here they charge $150 for a full flash back to STOCK---They do it for me all the time especially on diesel's where many people use handheld tuners to tune their trucks but forget to return the tune back to stock before selling--hence they are locked---

Chappy1062

Thanks for the insight. I'll contact another local dealer and ask the question......

Mike@DiabloSport

I have always understood the seed/key to be the same for a read or write, if a full flash is all it takes to get around a locked PCM it would be good news for countless people who have replaced locked PCMs or paid others to unlock them.

The example of handheld tunes being left in trucks does not really make sense to me, as I have never seen a handheld that locked a PCM...?

tblu92

Mike sorry didn't mean to imply that Diablo locks their tunes---I don't consider Diablo a "handheld tuner" as the name implies--Your software is far superior than what most people consider a "handheld" tuner.
Without naming brands LOL
More specifically I should clarify that most all the trucks that I am speaking about that had locked tunes were DIESELS--and the only way to get then UNLOCKED was via a full flash either from a dealer or a automotive diagnostics shop that has alternate software available.
I agree with you that on GAS engines especially on newer models it's more about the "Seed" and the "Checksums" not matching stock-
I know sometimes on a gas engine a full flash will unlock it--Sorta hit or miss--I was trying to give the poster one last option to try before he went to the extreme of buying a new ECM

Mike@DiabloSport

I gotchya, I didnt think you meant ours, but I still dont think we are on the same page as far as a locked PCM. If its locked, the seed/key has been changed, and no dealer tool can get around that from anything I have ever seen unfortunately.

tblu92

Ok Mike thks I always commend you and your software on the forums if you didn't know-- I have been able to correct the checksum errors with EFILIVE if that is the only issue but again mostly always on diesels--

Chappy1062

I thank you both... My goal is to make the car right. If I could do so without the additional cost of replacing the ecm that would be a bonus. Thanks