1999 Regal PO481

Since the fans are working, it sounds like an intermitant problem that may involve wiring, connector or componenet failure. A relay may be starting to stick but not all the time. I would pull the cooling fan relays (3 of them) and get a look at the terminals for any corrosion or similiar. And then check the connections at the pcm and the area behind the fuse box for any abnormalites. But before doing all that, I would clear the codes and drive it and see if the problem is still active.