instrument cluster coding algorithms

Discussion in 'Automotive Electronics' started by bmiller2, Oct 11, 2017.

  1. bmiller2

    Thread Starter New Member

    Oct 11, 2017
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    I apologize in advance for this long explanation I am a newbie when it comes to programming.....First let me explain what it is that I am trying to accomplish.... I work for a car dealership and we import vehicles from Canada into the USA... We are responsible for converting the vehicle instrument clusters from Metric to USA Imperial...one of the ways to do this is to swap out the cluster with an American cluster obtained from a salvage yard and to reprogram that salvaged cluster with the correct miles to match the original miles on the car.. i have been able to read and write to the eeprom chips using Xeltek IS01 programmer...when looking at the code on the chips and while knowing current miles stored on the chip, I can take the known miles and convert them to hex and then look for that hex code in the chip and that way i know what piece of code to adjust... but i ran into one that i cant seem to figure out...typically I take the known miles in denary form and convert them into binary and then take the binary and convert it to hex which allows me to search the code for that piece of hex and then i know what piece of code to correct...the one im having a problem with does not seem to work with that process, like im missing a piece of the conversion formula...so i sent out the bin dump file to an outside company who converted the code for me at a cost of $35...So now i have the before and after bin files... I have compared the two and i find the changed code in line 000000A5...that line of code was corrected but i cant seem to decipher how they took the known miles on the chip and converted them to hex in order to find the right piece of code.... if i attach the bin files both before and after maybe you can tell me the formula used....the FIRST bin file is called "2007 jeep compass american" and the SECOND bin file that was corrected is called " 2007 modded jeep compass american "...the miles on the first bin file is 208420 miles possibly stored as kilometers 335419 and it is stored in line 000000A5 and the piece of original code that was changed is " E0 1F 69 13 7A 0D" ... the 2nd bin file( the corrected one ) has corrected miles of 79036 likely stored in kilometers 127196 on line 000000A5 and the new hex code is DB 65 5C 07 1A 01.....I have tried every conversion i can think of from hex to binary to decimal and more but i cant decipher that piece of hex.
    I have both bin files for you to look at and maybe you can tell me how they took the known miles of 208420 and converted those miles to hex, then having identified that piece of hex as ( E0 1F 69 13 7A 0D ) therefore allowing them to replace it within the file with the corrected hex of ( DB 65 5C 07 1A 01 ) which represents the corrected miles of 79036.....for some reason this forum wont allow me to attach BIN files ...says wrong format...but i am a newbie so im sure im making a mistake on that as well....I can send anyone interested the BIN files to examine..I am willing to pay for the tech support...my email is <SNIP>

    Moderators note: removed email to avoid spam
     
    Last edited by a moderator: Oct 11, 2017
  2. bwilliams60

    Active Member

    Nov 18, 2012
    850
    136
    What is the year, make and model of this vehicle and what is the EEPROM number on the cluster?
     
  3. bmiller2

    Thread Starter New Member

    Oct 11, 2017
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    0
    it is a 2007 Jeep Compass, chip is 93c76

    im not sure how to upload the bin files on this forum so you can see the code...sorry, im a newbie
     
    Last edited by a moderator: Oct 11, 2017
  4. bmiller2

    Thread Starter New Member

    Oct 11, 2017
    8
    0
    hello fellas, again , i am a newbie so please forgive... where is the best source for me to get schematics for vehicle instrument clusters? so i can power up the clusters while on the bench?
     
  5. debe

    Senior Member

    Sep 21, 2010
    1,031
    214
    Usualy the wiring diagram for the vehicle shows the feeds to the instrument panel. I also cut of a section of the wiring loom to the instrument panel from the wrecked car, so its easy to power up.
     
  6. bwilliams60

    Active Member

    Nov 18, 2012
    850
    136
    PM me and I will see if I can get you a diagram for this unit.
    On another note, what about just moving the EEPROM from one unit to the other and then setting it to read miles?
     
    Last edited: Oct 11, 2017
  7. bmiller2

    Thread Starter New Member

    Oct 11, 2017
    8
    0
    Thanks , I'll check the wiring diagram.
     
  8. bmiller2

    Thread Starter New Member

    Oct 11, 2017
    8
    0
    Thanks bwilliams60. Yes I can move the eeprom from the Canadian cluster to an American cluster but I don't know how to have it ready in miles so to me it seemed easier
     
  9. bmiller2

    Thread Starter New Member

    Oct 11, 2017
    8
    0
    I don't know how to adjust the hex code to display in miles ... I'm sure there is away to do that mabey in the VIN
     
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