Problems with BBF Black Box Flashing on E40 PCM

[Treurentner]

Hi,

any recommendations for a E40 PCM in Corvette C6?
After a flawless BBF I got a corrupted data segment with wrong checksum after reading the PCM (that was in in non start condition after the datasegment flash).
OS is still availiable, PCM was BBR readable.
What is the best way to recover the PCM?
I attched the 3 zipped files
0037 is the original (flawless) readed file
0038a is the modified file before flash
0038 is the readed file (with faulty data segment) from the non operating PCM after reflash with the 0038a file.
At this time I have no Laptop with me - any chance to recover the PCM with BBF feature?
Any help is highly recommended.

Kind regards!

Marco

[Treurentner]

Hi,

finally found what happend:

the 0038a file was corrupted from EFILive Tuning Tool 7.5.6(109) itself.
No checksum calculation is made when the file is saved. Regardless if it´s under the old filename or a new one.
Only after reopening the saved file in the tuning tool it shows the wrong checksum in the engine calibration segment.
The AutocalV2 obviously makes no checksum verification so the corrupted file could be flashed to the PCM without any warnings.
So this needs to be fixed urgent in the EFILive software and may be a check routine can be implemented in the Flashscan software.

On the C6 it was additional necessary to disconect the battery for 15 minutes to get in ACC mode to reflash the original file, otherwise all CAN Modules mad some strange things.... I did everything with the Flashscan BBF and my PC at work... no Laptop needed.

Kind regards

Marco

[joecar]

Hi Marco,

I notified Tech Support of your finding.

Thanks,
Joe

[Blacky]

Saving a modified tune as a *.ctd file using the V7.5.6 build 109 will result in the segment checksums not being updated in the *.ctd file.

The workaround is to save the file as a *.tun file first which will update the checksums, then without making any other modifications to the calibrations, use File->Save As to save it as a *.ctd file.

A fix (build 110) will be available asap.

Regards
Paul

[Blacky]

The AutocalV2 obviously makes no checksum verification so the corrupted file could be flashed to the PCM without any warnings.
So this needs to be fixed urgent in the EFILive software and may be a check routine can be implemented in the Flashscan software.

FlashScan/AutoCal do not attempt to verify the segment checksums. However, each *.ctd file is protected by multi-level CRC and checksum verification routines. If any data is changed/corrupted after the file is saved by the V7 (or V8) software the FlashScan/AutoCal devices will detect that change/corruption.

The problem you are seeing is the V7 software was not updating the segment checksums, but it was computing its own CRC/checksum verification data and saving that to the *.ctd file. That meant that FlashScan/Autocal assumed the segment checksums to be correct since the *.ctd file CRC/checksums showed the file had not been changed/corrupted since it was saved. The real problem was that the V7 software was not updating the segments prior to writing the file.

That will be fixed in build 110 and it will be impossible (barring any further bugs) to generate a *.ctd file with incorrect segment checksums.

The FlashScan and AutoCal firmware has a *.ctd version detection system and will be updated to prevent existing *.ctd files from being loaded. Only *.ctd files created with build 110 will be allowed.

Regards
Paul