These are the tests I performed to help the technicians diagnose the problem.
You can download the video and this text, or watch them online, from my server at:
https://castelo-branco.org/Burchda/burchdaR7ProDualMotor.mp4
https://castelo-branco.org/Burchda/burchdaR7ProDualMotor.txt

Considerations:
. Whenever I move the rear wheel backward in any display configuration, it produces the error;
. Whenever I move the rear wheel backward, when the display shows the error, there's a good chance the next time the display is connected, it won't show the error. This works whether the display is on or off.
I don't remember if I tested with the battery disconnected, but I have a feeling it also works, since it seems to have something to do with the position of the motor on the wheel axle (magnets?). Furthermore, if the bike is turned off after the error, the error will appear on display when it's turned on again, even if there's no residual current in the system.
. In all error scenarios performed, the rear motor may produce a brief clicking sound, the wheel may not move, might roll slightly or a lot, but never more than a quarter of a turn.
. Moving the throttle and at the same time locking with the brake the rear wheel does not produces error;
. When the display is off (but the battery is connected to the controller), using the throttle does not "wake up" the display with the error.
Even though the front engine works, it is not possible to ride the bike anyway.


All stages of the tests (9) are numbered in the upper right corner of the video.
1- Battery Key ON, Display, Error 24.
2- Display, Throttle - no error nor activity on rear motor; when manually rotating the wheel it produces the error.
3- Display, Back Motor, Throttle - wheel rotates and produces the error. Wheel moves a little bit.
4- Display, Front Motor - works OK; rotating back wheel produces error.
5- Display, No Motors, Throttle - no error; rotating back wheel produces error.
6- Display, Both Motors, Throttle - Front motor OK; back Motor Error.
7- Display, Back Motor, Throttle. Error. The wheel only moves slightly and produces a little sound.
8- Display, Back Motor, manually rotating forward the rear wheel - OK; rotating backwards produces error.
9- Display, Back Motor, Throttle - Error. The only difference this time is that there is a very brief movement of the wheel.

Question:
Can I try to use the front Motor cable on the rear Motor? The objective is to check if there is something wrong with the rear cable or connector but I don't know if there will be incompatibilities. In this case to do the test I understand I need to select the front Motor on the Display.

Thanks.
luiz