Guide Mazda2 DE factory cruise control retrofit

So this one


Mine is a Japanize built (JDM) 2008 MY Mazda 2 Genki that was Australian delivered. Ie the vin number starts with "JM"
I had been trying to help another person in Australia get it working, but that car was built in Thailand and has the vin number starting with "MM".

anyway, back to your programing.

line 7 is where you have to change a bit to activate the cruise control. This is where i changes F11E to F320. This change is a combination of two things.
When you convert that 4 character number from Hexadecimal to Binary, you will see that the following has changes.

F114 = 1111,0001,0001,1110
F320 = 1111,0011,0010,0000

now i have put the commas in to separate out the individual bites.
the last two bites (8 binary bits) are a check sum.
by changing the red 0 to a 1 we have actually added a binary value of 2 to this line. So we have to increase the value of the check sum for the entire line by 2 as well. ie
Binary value:
00011110 + 10 = 10,0000

converting this number back into hex gives us the 20


So this is how we derive the value that we need to put into the line 7.

now as we have added 2 (binary 10) to line 7, we have to subtract that same value from the overall file check sum in line 25, hence my 29 becomes 27.

I would need to see what your original PCM values were.
Hopefully you have a JM made car.

I have a photo album on M20 face book owners group that shows where all the wiring goes.

regards Ryan = AKA Ezakimak
 
So this one


Mine is a Japanize built (JDM) 2008 MY Mazda 2 Genki that was Australian delivered. Ie the vin number starts with "JM"
I had been trying to help another person in Australia get it working, but that car was built in Thailand and has the vin number starting with "MM".

anyway, back to your programing.

line 7 is where you have to change a bit to activate the cruise control. This is where i changes F11E to F320. This change is a combination of two things.
When you convert that 4 character number from Hexadecimal to Binary, you will see that the following has changes.

F114 = 1111,0001,0001,1110
F320 = 1111,0011,0010,0000

now i have put the commas in to separate out the individual bites.
the last two bites (8 binary bits) are a check sum.
by changing the red 0 to a 1 we have actually added a binary value of 2 to this line. So we have to increase the value of the check sum for the entire line by 2 as well. ie
Binary value:
00011110 + 10 = 10,0000

converting this number back into hex gives us the 20


So this is how we derive the value that we need to put into the line 7.

now as we have added 2 (binary 10) to line 7, we have to subtract that same value from the overall file check sum in line 25, hence my 29 becomes 27.

I would need to see what your original PCM values were.
Hopefully you have a JM made car.

I have a photo album on M20 face book owners group that shows where all the wiring goes.

regards Ryan = AKA Ezakimak
That's my PCM module data fortunately my car is JDM made. I'm still struggling to understand, well everything ill be honest. Coding has never really been my thing and this just proves it haha. Thank you for all your help Ryan!
 

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