I was told I need to change the Mask ID at offset 08 to the value AA. which is supposed to be the 9th byte in the file.

I am trying to use the Hex editor in Tunerpro and I can't determin what is the 9th byte.

All i see are rows labled
00000000
00000010
00000020
00000030
00000040
00000050
00000060
00000070
00000090
000000A0
and so on you get the point.

for some reason the $EEb mask i downloaded from craigs file section dosen't calculate the checksum properly for my car.

I've included a copy of my bin for reference in case I have some other flaw in it.

 

might want to do some reading up on what bits and bytes are, how things are represented in hexadecimal, and all that jazz. lots of pages on the web out there. but here's a short brief explanation.

a bit is a single logical 0 or 1.
a byte is 8 bits.
a byte is often represented as a hexadeimcal (power of 16)
a byte can represent 256 distinct values (0..255).

example:

hex value = bits = decimal (power of 10) value
00 = 00000000 = 0
01 = 00000001 = 1
02 = 00000010 = 2
03 = 00000011 = 3
04 = 00000100 = 4
0F = 00001111 = 15
10 = 00010000 = 16
AA = 10101010 = 170
FF = 11111111 = 255

now as for your rows, you have something like this (note that i'm using RANDOM data values):

00000000 AB CD 1F 2E 3F 27 39 2A 9A 9B 91 7A 3F E7 A3 FF
00000010 BB CA 1E 1A 37 67 A9 BA 3A AB D1 BA 3A E1 AA F1
00000020 A7 9D 3F 27 32 21 3B 21 9F 9D 9A 73 3F E2 AF 9F

The first value, AB, in the first row, is offset 0 (or 00000000).
the first value, BB, in teh second row, is offset 10 (or 00000010).
the last value in the third row, 9F, if offset 2F (or 0000002F)

offset is simply how many bytes from the start, where offset 00 is defined as "the starting byte". Offset 01 in the above example is CD.

So, in THIS example, using random data, the value at offset 08 is 9A.