Sounds like a ground problem dirty or loose? I would first take a battery or a jumper box and hook 12 volts right to the plug end of the spreader to see if the spreader or wiring and controller.
If spins good then means in the controlller or wiring forward, check connections. If doesn't spin good then remove bottom motor cover plate, check the 2 spade connectors at the motor even try to hook 12 volts right to that and check the spinning.
If you have the manuals from the unit it sould show you what that code means ( don't have my book handy, sorry).
If you do need a motor PM me and I can let you know who has one in stock and the prices, Just had to put a motor in mine today
Happen to have my manual here. The EO means no electric getting to the motor. As said, check all the connections\wiring for a loose or broken connection. Had that happen the other day to me, the plug had been disconnected completely from snow banks I guess LOL. Not gonna spread too much salt with it unplugged. The fun we deal with at 3:00 AM