2008 2.5L Colorado with 2011 5.3 swap. ECM access issues.

[Zapo]

Customer did engine swap and used a stock tune ECU from Flagship One. Drove it for awhile, now they did camshaft swap and wants me to tune it. ECU would not read at all won't even start to read, acted like when I try to read a locked EFI live tune. So I tell customer I need a stock GM computer to start with, so they take there stock 2008 4 cylinder ECU and purchase stock tune online, paying OEM data license fees and using J2534 pass through device programmed the ECU. Now I can do a full read of the ECU but when it comes time to save the file, it shows file is locked and I need to ask the original file owner to unlock.

Any ideas on this? I also tried to change a VIN on a file that I had from a 2012 5.3 Colorado, but as you guys know, that did not work, but I did manage to waste 2 credits in that process.

[Zapo]

Just an update on this for others who might be fighting the same thing, been trying for some help with tech support. They say the serial number not reporting in the ECM. Gen 4 GM PCMs are particular in regard to what OS is programmed into the ECM. If this ECM was programmed with an incompatible it can affect the NVRam. In the past, we have seen an incompatible OS written and x35 and x36 errors report that would mimic a tunerlock on the ECM. Not sure if this help anyone, It maybe a why, but it does not seem to help me solve with problem without trying a third ECU.

[blindsquirrel]

12678511 is '08-down, '09-up calibrations would need a different service number, 12678512. (there are a bunch of interchange/reman numbers for each of those, but those are the two basic early/late numbers)