Info on Yazaki48

[QB89Dragon]

I'm trying to get a 2000 Toyota Tacoma dash up and running.
Instead of the typical please fix this file for me, I'd really like to figure out Yazaki 47 / 48 for myself as I like a good challenge and have a background in maths / electronics.
I've established that it's not Yazaki17 algo.

So far I have the following reference milages tested on my unit:

(hex) = (displayed milage)
2D08 = 110500
2809 = 112500
1409 = 111590


F80F = 196272
F80E = 183984
F923 = 442000

???? = 252005 <- the milage I'm trying to encode

There's clearly a swap-over in the XOR'ed bytes from 00 to FF depending on some value in there.

There's 96 repeated two-byte copies of the calculated milage in the binary dump, so we can assume that dividing the milage by 96 or a compliment thereof is a likely step.

Any other info would be really helpful as I'm hitting a wall here trying to decypher this, and I think this info would help out others trying to DIY things a little bit. Thanks!

[QB89Dragon]

Ok, just a follow up. I figured it out. Here goes:

Take your mileage, divide it by 48 (96 bytes worth of two byte words = 48).

So 252005 / 48 = 5250 (dec)

Convert that to hex, 0x1482.

Swap the byte order (little endian), so 0x8214.

So fill up all 96 bytes with repeated [82 14] with a hex editor and bam, your mileage is programmed!

IMG_3242 2.jpg