This means the fuser has an error. You can not reset the code even if the fault has passed without entering the service mode. If you need a service manual for this let me know and I will send you a link.
What code? Try entering service mode then turn off copier and turn it back on. (push these buttons in sequence Clear modes (yellow) 1 0 7 then hold the red stop button for 5 or so seconds you are now in test mode