Many people have reported that Russian tuners are able to Flash F10/F20/F20 ECUs. What they seem to do is open the ECU and short a pin to enable boot mode. Then they reset the DME time so it can be flashed. I'm not sure they're able to flash a custom map although I've been told that it's possible. But I'm pretty sure that this methods allows them to flash a 328 map into a 320, for instance.
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