$06FF Checksum Failure

[Agile One]

I have a client

[GMPX]

It is an easy fix, have a look at the calibration in the picture below. Change the value to 65535, re-save the file (either one) and you should be ok to flash it.

21719

[Agile One]

Resolved! Thank you for the quick response.

Incase I run into this again, I assume the same numeric string (65535) can be used with other controllers as well as the E92? Is this bypassing the checksum test or correcting the altered data from the 3rd party flash?

[GMPX]

There is a couple of companies that store CVN correction data after the 'end of calibrations' marker, when we flash the ECM before finalising it we check what was written is correct against the checksums. Unfortunately with those correction bytes outside of the checksum area it appears the flash failed.
Not every controller has the problem and not every one has the correction calibration, but if you strike it again then yes '65535' is the value that is needed, the description explains it.

Cheers,
Ross

[Mitco39]

Thats awesome that you guys made it possible for us to fix this ourselves.

[GMPX]

Yeah I do need to define the calibration (well the location) for every OS but most of the common stuff is done.

[Agile One]

I have this problem again with an E38 ECM. I have looked for the Checksum Fail Fix but it appears it has not been implemented with this controller yet. Any quick fixes or do I need to start cutting and pasting all the tables to a unmolested calibration?

[GMPX]

It should be in just about all E38's, what operating system is your file?

[Agile One]

Op Sys 12653674
I looked in the Operating System Patches directory and it didn't have the Chechsum Fail Fix. I didn't bat an eye at the error since I was sure I would be able to patch the checksum.

[GMPX]

Ok, try this updated .calz which has the option to reset the checksum issue some of these tuners cause.
Save the attached file in to here:
C:\Program Files (x86)\EFILive\V7.5\Calibrations\E38

Then reopen your ctz file and you should see parameter B9999

[5557nut]

I know this thread is old but I'm in dire trouble. I am working on a 2010 Chevy 2500 6.0L vin 1GC4KXBG3AF147376 OS:12636005.
I made a copy of the original tune. Then disabled the downstream O2s in the DTC type n mil. When I did the full flash, at the very end I got the checksum fail $06FF. Now the truck will not start
Nothing I do allows me to flash the computer and now 7.5 scan won't recognize the E38. There is no checksum fail parameter.
Where do I find the checksum patch or how do I fix this. Thanks

[Doc]

Have you attempted to full flash the original file? It probably has a Diablo tune or what not on it that is causing the issue. Once a tune file has been altered from factory with some can'd tune thing best not to mess with it unless you have THAT software and have permission to do so. Worst case, you have to have your local dealer or equivalent or greater capability flash it back to stock.

[5557nut]

Thanks for answering...yes I did try to flash the original but got the same error sooooo I guess it's to the dealer

[Doc]

Well, hold on just a min. Pm me.

[Phil_Miller_86]

I found this thread using the search, and I think this extra line of code from third party programmers might be the root of the problem I'm experiencing, but I have an older truck with a different PCM(?) so this may not be the place to find the answers I need. I will share the base info with hopes that someone can direct me to the right place?

2004 Avalanche 2500 (LS1B?) with a hypertech 3 tune that failed to uninstall properly. Truck won't start, I get an invalid checksum error that shows speedometer segment 8. I don't have a stock tune file because it had the hypertech on it when I purchased it.

[GMPX]

It is unlikely on the older PCM's this is the problem, but you'd need to post up the Hypertech tune you read out to be sure.

[Phil_Miller_86]

It is unlikely on the older PCM's this is the problem, but you'd need to post up the Hypertech tune you read out to be sure.

I started a thread here: https://forum.efilive.com/showthread.php?30402-LS1B-8-1-4l85-with-failed-hypertech-tune-assistance

When it allows me to upload files I will post it up and hopefully someone can help me out.