I have been trying to find out how the Bosch antituning SW works, and the best guess I have is that it accumulates the number of pulses from the wheel sensor over a ride, and compares that with what it expects (within some broad limits) given the power output, motor RPM, cadence and input torque from the pedals. The motor has no idea of what the gear ratio to the wheels (afaik) so it cannot be accurate but can trap really silly values.
If you have a tuning chip there will be fewer pulses sent to the motor than are generated by the wheel magnet, and if this deficit gets too high, the motor will log an error.
This jibes up with the story told by tuning chip makers, that you have to leave the bike on for 60 sec. at the end of the ride, while the chip puts back those "missing" pulses. You can see the speedo flashing during the cooldown period in this short video:
which is what you expect if pulses are being squirted in while the pedals are not turning and the motor is not running (like a little downhill run at the end of the ride).
Any thoughts? Neither Bosch nor the tuning chip makers will talk on this, but am I on the right track here?