MBS206

Hey Roland, Id hazard a guess the XOR check sum is likely a CRC-8 checksum. Nissan are known for it on critical messages too. Security type challenges ive seen documented (by the manufacturer) for other vehicles, is often taking the original value, inverting every bit. Add specific values to certain bytes, invert it all again, and then send it as the challenge response. All of it carries normally something like a CRC8 checksum too. This is all on the CANBUS not what the remotes are using.