2007 or 2008 harley soft tail speedo mileage change

[sideshow]

hi all does anyone know which chip i need to read in this harley speedo
the 8 pin chip has mcz 33390 on it
i googled it for data sheets but i think my wellem programmer doesnt do this chip
any info is greatly appreciated

thanks

431621

[clusters]

I don't think that is an eeprom, what's on the other side of the board?

[sideshow]

thanks so much there is a 93c66 on the back
your a life saver thanks again

[sideshow]

hey clusters
this is the dump i got and the milleage is 9242
does it seem correct cause the software i have is abit wrong when i read it and then select 9242 kms on the software

431826

i read it using my wellem programmer which swaps bytes on those chips when i read it

i think customer needs to to be up to 24000

thanks

[daxt0r]

Try this an provide feedback.

[clusters]

@daxt0r, your calculation is byte swapped and will give error.

Here is 24000 Km

[daxt0r]

thank you for the correction, never did a manually input change like this before.

I'm here to learn, so thank you for pointing that out.
Can you please explain so i can do better?

I was editing in ETSMART hex editor with 93C66 selected an 512x8 ordering, was i suppose to be using 256x16?
Does it have to do with the chip being 8 or 16-bit? Is there anyway to tell that because most vehicles i have seen just say 93C66 or 93C56.
Say I dump the chip using 93C66_8 and 93C66 how do i tell which is valid, and do i use 512x8 to edit the 8-bit and the 256x16 to edit the 16-bit. Or do i always edit in 512x8 or 256x16 regardless?

Or is it simply that the calculator i used outputs in different endianess meaning i have to swap the bytes manually when entering into the editor?

I will gladly read any material rather than beg for help because this manual editing files without calculator is new to me but the purpose i came here was to learn.

[clusters]

Most if not all files should be read as 16 bit. Read in 8 bit you will see repeating bytes throughout the whole file, but is not always the case.

Knowing the endianess of the file is from experience and knowing the algorithm, or if you put the original mileage into your calculator and it is the correct algorithm it will be obvious which way it goes. ;)

[daxt0r]

Most if not all files should be read as 16 bit. Read in 8 bit you will see repeating bytes throughout the whole file, but is not always the case.

Knowing the endianess of the file is from experience and knowing the algorithm, or if you put the original mileage into your calculator and it is the correct algorithm it will be obvious which way it goes. ;)

thank you for the advice! I will definitely use this going forward!!!