Some questions understanding checksums for ECU flashing

**r3zon8** · 14th June, 2016, 10:15 PM

I read my original files from my DME using EU KTAG/KTM100 clone and now I have 4 files:

ECU - .DIM
Micro- .MPC - 4096K
EEProm - .E2P - 64K
Tuning File - .DTF - 4096K

I am planning to send my .MPC file for tuning service and I understand I must correct checksum before writing the tuned file to the ECU.

How do I make sure KTM100 corrects/calculates the correct checksum? When i attempted to write a file it asked me If I want to correct checksum- if i click Yes, it asks me for the original file. is this normal?

After the KTM100 writes the file- if i read the DME again will I see the same original AD53 checksum?

**tunertool** · 14th June, 2016, 10:53 PM

Almost all files have a checksum inside, they vary depending on ECU type. Most checksums are calculated while writing with decent tools.

KTM100 should calculate most checksums as it is a clone of Trasdata which is a decent tool. Yes its normal for it to ask for original file for comparison and then creates checksum based on changes.

If you read the file again it will not be the same because the file is different.

**r3zon8** · 14th June, 2016, 11:03 PM

got it. thank you for explaining that. I thought the tool would force the old checksum on the edited file

**Roncella** · 19th June, 2016, 08:38 AM

Did this work for you? First time using mine. I had a Volvo C30 D-4 which has an edc17.
I read the files with my KTM100. I had the modified file back from an Alientech dealer and when I tried to write it to the ecu it asked me to check sum, it came back saying checksum error. I continued anyway but the car would not start so I had to dump the original file back in and call it a day

I can't find any info on this and doesn't help that I am new to the ktag100. The v6 seem to do this automatically. Any help advice would be greatly appreciated please as to how to work this properly

**jakkeviet** · 19th June, 2016, 11:57 AM

can you send file ?

Originally Posted by Roncella

Did this work for you? First time using mine. I had a Volvo C30 D-4 which has an edc17.
I read the files with my KTM100. I had the modified file back from an Alientech dealer and when I tried to write it to the ecu it asked me to check sum, it came back saying checksum error. I continued anyway but the car would not start so I had to dump the original file back in and call it a day

I can't find any info on this and doesn't help that I am new to the ktag100. The v6 seem to do this automatically. Any help advice would be greatly appreciated please as to how to work this properly