Yaris ECU Reverse Engineering Progress

[gboezio]

I read that some EPROM will erase themself if they are hacked in some way, I just hope it's not the case here.
If they do have encrypted their data, there's no way to decrypt unless we get the key, witch should be somewhere in the ECU.
Nothing is impossible, but this seem to be very hard to achieve.
We need more info on this EPROM, some spec sheet.

Originally Posted by Nexus1155

If i were trying to crack it through OBD, maybe, but ive dealt with encryption before on the Audi ECU's. When you are dealing with something that has direct contact with the MCU, i doubt there will be an encryption since it is such a mundane way of programming the ecu directly from the factory... Now if they removed a resistor to short out the communication, then ill be screwed...

A chat with a Toyota chief mechanic coud provide some good info on the "how" they reflash them, but it may be a simple hook the machine and press play...
If it's the way they change their maps, I guess it's possible to go trough there, the best tuners are all over the Supra, but I doubt that their ECU is as complex as this one.

[GeneW]

Originally Posted by gboezio

I read that some EPROM will erase themself if they are hacked in some way, I just hope it's not the case here.

Probably a checksum that is computed at the time of code compilation. That was one way to do it.

If the checksum doesn't add up the code will not run.

Gene