[solarstingray]

I had to have my c7 ecm replaced,

stupid dealership who sold it to me didn't know the prevous owner tuned the car and traded it in ,

of course they reached out to the previous owner who was clueless,

the dealership had to eat the 700.00 cost to put a factory untuned ecm in there to keep the warranty intact,

[jasonfichter]

Originally Posted by JANNETTYRACING

I have been wrong before but the way I understand it is you can not have 2 ecms and switch between them, the vehicle will not start on one of them.

If the dealer Syncs one the other becomes unusable.

They have security key that must be synced to all other modules in the car.

Ted.

That sucks! I just ordered an ECU. For $89 its worth a shot.

I was also recently told that the flash counter is kept in the BCM so having two ECU's doesn't matter. I would need two BCM's

[TJay74]

ECU is VIN tied to the car, cant just swap ECU as it requires the dealer to plug into the car and have the car on the GM Global system in order to sync the new ECM to the car.

[TJay74]

Also GM doesnt use a flash counter on the new ECM's either, last I read when I ws doing some research is the flash counter is only turned on in the diesel ECM's. As long as the ECM is flashed back to stock with the original OEM tune the dealer will never know as the CVN values will match.

[WhiteNight]

^^^^ Very interesting info. I wonder if the flash counter is simply something thats regurgitated without actual proof. Someone here has got to have a friend at Chevy that can find out.

[jasonfichter]

Originally Posted by WhiteNight

^^^^ Very interesting info. I wonder if the flash counter is simply something thats regurgitated without actual proof. Someone here has got to have a friend at Chevy that can find out.

It's definitely a thing. It's kept in the BCM.

[JFM-jr]

Im good friends with an A tech at a Chevy dealership. I remember talking to him about this tooic. He said GM requests a screenshot of a certain screen in the ECM. He told me it looks like jibberish but its something they can use to see if the ECU had been rewritten at any point. They will not look at specific data and say "well all the stock timing tables etc are stiil there so its good for warrenty". They can tell its not the original file even if every single table in the file is set back to stock. Once you "rewrite" the file its no longer original. The part about GMs global server being needed to get a different ECU to work is also true. GM has a vested interest in protecting itself in this area and they have $ to use technology available to help them with it. It wont be easy getting around it but thats not to say its impossible.

[TJay74]

Every module in the car is VIN tied now and the tech use the GM Global server to flash the firmware to those modules when they are replaced. Several tuners have said as long as the exact OEM tune is flashed back in that GM wont see the change as the CVN values will match back up, that is what GM is looking for in that screen shoot.

[JFM-jr]

Originally Posted by TJay74

Every module in the car is VIN tied now and the tech use the GM Global server to flash the firmware to those modules when they are replaced. Several tuners have said as long as the exact OEM tune is flashed back in that GM wont see the change as the CVN values will match back up, that is what GM is looking for in that screen shoot.

They are looking for more than just the information in the file. They keep track of the last known Calibration ID flashed to that VIN. They also keep track of when the actual dealer AND the Tech that signed in to perform it. He said GM is pretty strict about them not giving their sign in information to any other techs. He is a Master tech with GM and at his dealership they keep him on the Corvettes and Camaro platforms mostly. This guy is into performance hes like us and if there were a way around this Id hope hed know better than me. As for swapping ECM's he has done it and yes the GM global server is used as I stated earlier. He said its a fairly involved process (said its a pain in the ass actually) the server needs to sync with the vehicle at different points during the process. This swap would also be tied to to VIN's history in the database even if its not warrenty work and paid for by the customer. Swapping the ECM is probably more about theft deterrent than anything else think about it buy a 200 dollar ECM and you could install it and drive a car away. He did mention on vehicles back in like 2012 flashing the original file back onto the ECU would work to cover any warrenty but on a 2014 C7 it was kicked back. The screenshot of the calibration ID's that GM requests he again has confirmed is not something he can make heads or tails out of by looking at it. He said its a bunch of jibberish on the screen but it is information that obviously GM can decipher. He also mentioned this has begun for transmission replacements as well they request the Calibration screenshot of the TCM. GM is not stupid they are well aware of what goes on and if you dont think a company of this size is gonna try and protect itself your nuts.Maybe at some point somebody will test the theory out and post it here and the information im being given is wrong id be fine with that.

[cmitchell17]

Originally Posted by JFM-jr

They are looking for more than just the information in the file. They keep track of the last known Calibration ID flashed to that VIN. They also keep track of when the actual dealer AND the Tech that signed in to perform it. He said GM is pretty strict about them not giving their sign in information to any other techs. He is a Master tech with GM and at his dealership they keep him on the Corvettes and Camaro platforms mostly. This guy is into performance hes like us and if there were a way around this Id hope hed know better than me. As for swapping ECM's he has done it and yes the GM global server is used as I stated earlier. He said its a fairly involved process (said its a pain in the ass actually) the server needs to sync with the vehicle at different points during the process. This swap would also be tied to to VIN's history in the database even if its not warrenty work and paid for by the customer. Swapping the ECM is probably more about theft deterrent than anything else think about it buy a 200 dollar ECM and you could install it and drive a car away. He did mention on vehicles back in like 2012 flashing the original file back onto the ECU would work to cover any warrenty but on a 2014 C7 it was kicked back. The screenshot of the calibration ID's that GM requests he again has confirmed is not something he can make heads or tails out of by looking at it. He said its a bunch of jibberish on the screen but it is information that obviously GM can decipher. He also mentioned this has begun for transmission replacements as well they request the Calibration screenshot of the TCM. GM is not stupid they are well aware of what goes on and if you dont think a company of this size is gonna try and protect itself your nuts.Maybe at some point somebody will test the theory out and post it here and the information im being given is wrong id be fine with that.

Does anyone know what kind of security features are on the ecm that come with gm in performance crate engines? I know by law they have to have the challenge response seed key for obd purposes, but does gm plan to lock it down to where they are the only ones to make"performance" calibrations to use with their parts? I really hope they don't implement what they did with the Duramax ecm to all the rest of the controllers.

[Jamesborg]

I have a quick question for an Ecm swap I have a 2016 V6 Camaro supercharged and I want to run a flex fuel kit but the V6 ECM does not have a pin out for flex fuel. Would it be possible to swap a SS ecm in?