2nd and OD uses the same band, just a different piston that applies. Usually OD starts slipping and 3rd stays fine for a while, but will go out too. Anyway you go, your going to be looking at a rebuild. The EPC (electronic pressure control) soleniod usually goes down causing a low pressure condition that will help smoke the clutches. This can and will cause different things to occur in the tranny. Only my 2 cents and times spent with them. I had 1 that had all the gears in OD but would go to neutral in low gear. And in was the EPC. I hope it's something simple but sounds like bigger problems.