Algorithm for Seed Key

[croudfreak]

Hello,
I’m having problem to find a solution to my issue, I make a log and receive 2 bytes as SEED, and 4 bytes are the KEY to send to the ECU in my communication, I’ll be clearer.
I make the communication with the ECU, then I send a command to request the SEED, the ECU sends to me 2 bytes, then I have to send the key, which are 4 bytes are right key. What I need is the algorithm to calculate the KEY to send, since I have the SEED and the Result.

Received SEED KEY Sent
92 90 <<<<<<< if I receive this, how I get this >>>>>> 02 2A 7C 90
BC BB 31 A0 21 1F
73 90 17 A7 B7 60
19 CA 0B B9 53 3A
8A 53 01 4B BE F4
(OS. This SEED’s and KEY’s are valid).

I hope someone could help me to solve this problem; I’m took several days to analyze this and haven’t any result.

Regards.

[Holden202T]

im not sure many people will be able to help without more information, what is the model of the car, what computer, engine size etc anything you can provide that might help.

[VL400]

Yep, some more info would def help The seed/key combo used in early Aussie (and some US) PCMs is generally 2 bytes for each. The newer style PCMs use a rolling seed, do you get a different seed each time you request it?

[croudfreak]

i'm loggin a DODGE RAM - 2007

every time i've request the SEED the ECU send a differnt one, like you can see above

Received SEED.................................................KEY Sent
92 90 <<<<<<< if I receive this, how I get this >>>>>> 02 2A 7C 90
BC BB......................................................... 31 A0 21 1F
73 90......................................................... 17 A7 B7 60
19 CA......................................................... 0B B9 53 3A
8A 53......................................................... 01 4B BE F4
(OS. This SEED’s and KEY’s are valid)

[VL400]

Not sure on the algorithm used in rolling seed PCMs

[antus]

If its rolling, it must be generated in the ecu. Can you get a bin and post that?

[croudfreak]

You want the seed's and the key's in binary ?

[antus]

The whole binary, if you have a way of retriving it. No promises, its all time, but if I ever get some spare time it would be fun to try and figure it out.

[croudfreak]

__________SEED___________________________________________KEY_______________________
|.....92................90..........|.............02.................2A................7C................90....|
|__________________________|________________________________________________________|
|10010010........10010000......|.........00000010........00101010........01111100........10010000|
|__________________________|________________________________________________________|
|.....BC................BB..........|.............31.................A0................21.................1F...|
|__________________________|________________________________________________________|
|10111100........10111011......|.........00110001........10100000........00100001........00011111|
|__________________________|________________________________________________________|
|.....73................90..........|.............17.................A7.................B7................60...|
|__________________________|________________________________________________________|
|01110011........10010000......|.........00010111........10100111........10110111........01100000|
|__________________________|________________________________________________________|
|.....19................CA.........|.............0B.................B9.................53.................3A...|
|__________________________|________________________________________________________|
|00011001........11001010......|.........00001011........10111001........01010011........00111010|
|__________________________|________________________________________________________|
|.....8A................53..........|.............01.................4B.................BE................F4...|
|__________________________|________________________________________________________|
|10001010........01010011......|.........00000001........01001011........10111110........11110100|
|__________________________|________________________________________________________|
|.....2C..............BA...........|..............2D................B5................0B..................78...|
|__________________________|________________________________________________________|
|00101100........10111010......|.........00101101........10110101........00001011........01111000|
|__________________________|________________________________________________________|
|.....66................66..........|..............1F.................9E................54................9C...|
|__________________________|________________________________________________________|
|01100110........01100110......|.........00011111........10011110........01010100........10011100|
|__________________________|________________________________________________________|
|.....06..............7D............|..............17.................AC................EF................CD...|
|__________________________|________________________________________________________|
|00000110........01111101......|.........00010111........10101100........11101111........11001101|
|__________________________|________________________________________________________|

As you request, i post the seed's and the key's in binary, i supose that is what you want
by the way, thanks for the attention

[Jayme]

no he means the tune, as in the bin file off the pcm