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sanya686



Member Since: 21 May 2016
Location: Moscow
Posts: 5

Russia 

Hello! Please help me with the calculation of checksum(crc-32) file .vbf . When I think, gives the difference with the original CRC-32 in file vbf. Sincerely, Alexander.

Post #299096 21st May 2016 4:18 pm
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sergio977



Member Since: 08 Jan 2016
Location: Italy
Posts: 128

Italy 2007 Freelander 2 TD4 S Manual Orkney Grey

ouch...Alexander, I think your question is for a "very-advanced-Sunday-spanner-warriors" Very Happy

Post #299219 23rd May 2016 7:17 am
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

Do you look for an application to do this calculation or do you want to know the details about which memory block is used in this calculation?
I've posted on lr-club.ru a small set of information regarding this. You can look there.

Post #299237 23rd May 2016 9:44 am
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sanya686



Member Since: 21 May 2016
Location: Moscow
Posts: 5

Russia 

Alex. I learned that you laid out on LR-club.ru. I have problems with calculate crc-32. HxD editor, issue is not something that should be, and that asking for help, how to count correctly.

Post #299250 23rd May 2016 12:04 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

Below there is a file where you can see from where to where (the selection) is the data block for CRC32.
You can extrapolate it to your file. But I believe you are thinking too much with this CRC32, the SDD is not taking it into account....

Click image to enlarge


Last edited by alex_pescaru on 14th Oct 2020 11:44 pm. Edited 1 time in total

Post #299269 23rd May 2016 2:54 pm
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sanya686



Member Since: 21 May 2016
Location: Moscow
Posts: 5

Russia 

Thank you very much for the clarification. But I thought that SDD and gives an error for this checksum. I threw thoughts tied to the date of a file changes, so stopped at this crc-32. How do I know crc-16 is needed to verify the integrity of the control unit. If possible, send in the right direction.

Post #299274 23rd May 2016 3:57 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

From my experience, at least on my car, the SDD doesn't check the CRC32.
But checks, without doubt, the CRC16 used for every block of data when flashing that information to an ECU.
The integrity of the ECU is verified only by reading its content (program and data flash memory) and comparing it with the original.
I don't know if this is what you've asked... if not, please explain me again what do you need...

Post #299279 23rd May 2016 4:55 pm
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sanya686



Member Since: 21 May 2016
Location: Moscow
Posts: 5

Russia 

I want to program a change .vbf using SDD, but I constantly when programming a message appears incorrect checksum file and therefore it is deleted from the catalog flash. So I ask you to help how to fix it.

Post #299282 23rd May 2016 5:33 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

In a VBF could be as much as 3 different CRCs.
The CRC32, for the whole file.
The CRC16, for each data block from the VBF.
The CRC(?) inside the data block, CRC verified by the ECU itself.
For example, for the EDC17 engine ECU (after 2011), even if you correctly set the CRC32 and CRC16s, if you don't properly recompute the data CRCs inside the firmware itself, you will get those CRC errors from SDD.
But again, the CRC errors are given by the ECU and only presented/showed to you by SDD, not verified by the SDD.
Get in touch with Greg777 - I believe he's also in Moscow - and he will explain better.

LE: I will ask later a moderator to split this topic into a new one, with a more relevant title - let's say "VBF CRC calculation", because what we are talking here has nothing to do with EGR modification/blanking, so if you will not find here anymore our discussion, look for that new topic.

Post #299290 23rd May 2016 7:01 pm
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sanya686



Member Since: 21 May 2016
Location: Moscow
Posts: 5

Russia 

Thank you, it was clear. Please Greg777. Sincerely, Alexander.

Post #299294 23rd May 2016 7:28 pm
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

Some minor add to this old thread...
Link to VBF Tool, for viewing/modifying VBF files structure
https://cloud.mail.ru/public/M6FW/ScGcAgqZ1

For conformity and for being fair, quote from readme.txt
"VBF Tool is freeware and available from Volvo Car Corporation."

Post #398330 14th Oct 2020 11:46 pm
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MotionInc



Member Since: 17 Jun 2019
Location: North America
Posts: 1304

Canada 2008 LR2 i6 SE Auto Tambora Flame

^^^^^Thank you, that tool could be very useful. Thumbs Up

Post #398332 15th Oct 2020 8:04 am
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Vanny



Member Since: 06 Dec 2015
Location: Cheshire
Posts: 437

United Kingdom 2013 Freelander 2 SD4 XS Auto Santorini Black

A note of caution, VBFTool is not forward or backwards compatible. VBFTool 2.xxx can only be used with Version2 of the VBF format, something that has caught me out in the past!

Post #398339 15th Oct 2020 10:28 am
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alex_pescaru



Member Since: 12 Mar 2009
Location: RO
Posts: 4640

Like they say: let someone point out the single one cloud on the sky.... Laughing Laughing

For sure, if someone is interested, will observe that, if it's the case.
But many VBF files in SDD, if not all, can be handled with the above program, which is the main point.

I am thinking that if something I am sharing can help someone, then it's a good thing.

Post #398360 15th Oct 2020 4:37 pm
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