VBF modifying
Posted: Sun Feb 01, 2026 9:03 pm
Hi!
I am currently working on decompiling firmware from the instrument cluster of a Ford Edge from model years 2015–2024. Models before 2019 use external flash, while models after 2019 are MCU-based. I am trying to understand the firmware structure (how it is built), but I lack proper documentation on how Ford or Volvo create such files so that they work correctly with the vehicle modules.
I would like to change (replace) one of the existing languages with my native language, because from the factory these clusters support only a few languages (English, Spanish, Portuguese, German, French).
While analyzing the structure of the cluster update file NT4T-14C026 , I discovered that:
the VBF file is compressed using LZSS 10-bit/4-bit,
it contains CRC16 and CRC32 checksums.
To correctly replace a language, all of checksums inside BIN (converted from vbf) must be recalculated. It is not allowed to change the full word length in an existing language — for example, if the original word is “SETTINGS”, you cannot replace it with a word in another language that is longer than 8 characters, because this would break the entire table and the software will not work. You can, however, insert a shorter word and pad it with spaces (or fillers) in the unpacked *.bin file.
I won’t lie — this is a difficult topic for me, but I really want to understand it. I know that one Russian developer managed to develop a method to change the language to Russian and is able to do it successfully, so I would like to achieve the same, but for my own language.
However, it does not seem as difficult as it might appear at first glance, because based on the information I have found so far, the most important part is the checksums, which are verified by a routine in the processor. If the checksums do not match, the processor immediately bricks the cluster after flashing, its not just simple as changing only texts , proper language id and checksums are most important.
And now my question is:
Do any of you, dear colleagues, have a firmware file for such a cluster (KT4T, GT4T, NT4T, or LT4T) in which any language has already been replaced with another one? I am only looking for a reference — comparing two files would make it much easier to understand and reverse-engineer the structure.
Also, does anyone have any technical documentation related to the VBF format? , Google and forums has only couple informations about it . Checksum inside are CRC16 CITT , should be the whole data BLOCK , but ! there has to be something else going , even swapping SETTINGS to TESTXXXX and recalculating checksum for VBF (last two bytes in VBF are checksum of whole decompressed BIN data ) , it just bricks the cluster .
I am currently working on decompiling firmware from the instrument cluster of a Ford Edge from model years 2015–2024. Models before 2019 use external flash, while models after 2019 are MCU-based. I am trying to understand the firmware structure (how it is built), but I lack proper documentation on how Ford or Volvo create such files so that they work correctly with the vehicle modules.
I would like to change (replace) one of the existing languages with my native language, because from the factory these clusters support only a few languages (English, Spanish, Portuguese, German, French).
While analyzing the structure of the cluster update file NT4T-14C026 , I discovered that:
the VBF file is compressed using LZSS 10-bit/4-bit,
it contains CRC16 and CRC32 checksums.
To correctly replace a language, all of checksums inside BIN (converted from vbf) must be recalculated. It is not allowed to change the full word length in an existing language — for example, if the original word is “SETTINGS”, you cannot replace it with a word in another language that is longer than 8 characters, because this would break the entire table and the software will not work. You can, however, insert a shorter word and pad it with spaces (or fillers) in the unpacked *.bin file.
I won’t lie — this is a difficult topic for me, but I really want to understand it. I know that one Russian developer managed to develop a method to change the language to Russian and is able to do it successfully, so I would like to achieve the same, but for my own language.
However, it does not seem as difficult as it might appear at first glance, because based on the information I have found so far, the most important part is the checksums, which are verified by a routine in the processor. If the checksums do not match, the processor immediately bricks the cluster after flashing, its not just simple as changing only texts , proper language id and checksums are most important.
And now my question is:
Do any of you, dear colleagues, have a firmware file for such a cluster (KT4T, GT4T, NT4T, or LT4T) in which any language has already been replaced with another one? I am only looking for a reference — comparing two files would make it much easier to understand and reverse-engineer the structure.
Also, does anyone have any technical documentation related to the VBF format? , Google and forums has only couple informations about it . Checksum inside are CRC16 CITT , should be the whole data BLOCK , but ! there has to be something else going , even swapping SETTINGS to TESTXXXX and recalculating checksum for VBF (last two bytes in VBF are checksum of whole decompressed BIN data ) , it just bricks the cluster .