2012 Camaro $066FF Checksum Failure

[powerfreak]

Fellow tuners, I just completed an engine build on a 2012 Camaro SS for a customer. After the build, I pulled the file (car was originally modified, customer over-revved engine and valves kissed the top of the pistons) to make a few modifications to set the ECM for some wideband tuning. During the flash the script exited with $066FF Checksum Failure. Looks like this ECM has had tuner or a file EFI Live didn't like. I searched Tune File Depot for a good stock cal. to flash in and start from scratch but the file I need isn't on there. Would anyone happen to have a good cal. I could use to get me back going? The OS is 12649046 manual car. Any help is appreciated!! Thanks in advance!!

[GMPX]

What software versions are you running? We put a fix for this issue in some of the later OS's.

[powerfreak]

V8.2.2.272 and V7.5.7 (Build 278)

[GMPX]

Ok, if you want to post the .ctz file up here I'll fix it up for you.

[powerfreak]

I just updated to the latest versions and tried to reflash. That did not work either, still the same thing. I was able to try a file I found on here labeled LS3_tune_fix. Although it had a different operating system it was compatible. It did flash successfully, however, the engine seems sluggish and when I try to log the PID: Commanded AFRRATIODMA shows 0.38:1 instead of 12.5-14.7 as usual. I logged another E38 to rule out an issue with my software. That ecm read correctly. Can the "damaged" file be repaired? I'll post it up here shortly if it can be. Thanks in advance.

[powerfreak]

Just noticed your reply. Coming your way. Thanks!

[powerfreak]

Here is the file...Thanks again
18470

[GMPX]

Try this file, it is the same file you posted with the problem removed. If this works for you then you can continue to modify it as needed without worrying about the reflash problem reoccurring.

Cheers,
Ross

[powerfreak]

Ok, sounds great! Thanks a bunch

[powerfreak]

Well, the tune did load up and run. However it's doing strange things now. After the flash I opened 7.5 and started doing some logging. Now the commanded AFR is working properly but I've lost engine RPM during logging. Showed 0 RPM the whole time. I performed a calibration only flash and my engine RPM is back to working properly but now a check engine light. The code was for the crankshaft position sensor performance and when the engine is hot it will drag BAD when cranking. Pretty much just turn over and when each cylinder is nearing TDC just quit turning. Almost like the timing is sky high but its not or the battery is extremly weak but thats not the case either. Also if you look at the tune check out tables C0625-C0626 misfire tables. The RPM begins at 4800 and goes to 7800 in 600 RPM increments then jumps to 8192 RPM for the rest of the data in the row. Table C0621 starts at 4,800 RPM then drops to 450 in the next row and looks ok the rest of the way. I just really think I need to start over with a fresh unaltered file to get all of these bugs out of here.

Is there anyone out there with a known good calibration for a manual Camaro SS with the 12649046 OS? I tried the 12653252 OS and thats when I have the issue with the commanded AFR Ratio not reading correctly. My next step is to just disconnect the battery overnight to see if that does anything while I'm trying to find a good file. Although I doubt doing that helps me any.

[powerfreak]

Update....I GM flash a stock calibration into the ECM using their software. (TIS I suppose) I return the car back to my shop and read the ECM. Instead of them flashing it with the 12649046 OS it was flashed with the newer (I suppose) 12653252 OS. I tried to do some logging and the bug is back!! Commanded AFR Ratio is stuck reading at 0.38:1 while logging. Reflashed the ECM with the "fixed" 12649046 file and AFR reads correctly, however, the misfire tables are still screwy. Surely there's someone or someplace out there that has a good 12649046 cal. for a manual transmission so I can get this thing tuned and out of here. I'm getting behind screwing around with this thing. I don't care whats been done to the file....stock or modified...as long as it's a good one. If I had a way to convert a HPT file I'd be in business as there are 5-6 of those files over there no that site. Id just rather use EFI for all my tuning. If anyone has one please send it my way. Thanks in advance.