I have an ecotric lightning ebike and it is showing error 30 on the display (s700), when I looked in the manual it said it is a "UART receive error". The motor won't work and the display doesn't recognize when I move the bike tire... Help!
My guess is either a loose connection on the display plug or a failure of the UART chip in the controller or display. I don't know where the controller is located on your bike but if you locate it, look at the 5 pin connector that goes to the front of the bike. It probably has tape over it,
If reseating that does not fix the error, you'll need either the controller or the display replaced. Is it still in warranty?