Ninebot ESX Error Code 54
"Motor phase C (blue) disconnected - check motor-related cable"
If your Ninebot ESX(ES1, ES2, ES3, or ES4) or SNSC (1.0 or 1.1) is beeping or has a red wrench icon and flashes this code, read below.
If you clicked the wrong error code, go back to the Error Code Index.
As the message states, error 54 should be thrown when motor phase C (the blue one) becomes disconnected or damaged.
Remove the pole from the base and check that the phase is still connected and not damaged.
If that doesn't work you may need to replace the ESC/Controller Board.
If this didn't solve your issue or if you came to another solution, please let me know as this seems to be a popular error and I'm yet to be able to reproduce it yet.