the yale service book for this model does not list that alarm code.
if you have checked the start switch, the fuses, and all connections then...
i think your best bet is to pull the controller and send it to fsip and have them check it out, it could have something broken inside it.
i know in the past i've dealt with these and the main power cable standoff's inside the controller can break off the internal heatsink fairly easy with a strong jar like that. Also we had to go into the controllers before and make sure the ribbon cables inside were plugged in, they had a tendency to vibrate loose and zapi had us go in and reconnect them and use silicone to make sure they did not come loose again.
Just a couple ideas to try...