Mine did the same thing. The dealer said the trans was bad and thet they don't repair them, they just put a factory rebuilt one in. On the bright side, all sensors, torque converter, PNP switch, etc. are new and have a 1 year warranty. On the down side, it cost a little over $2000.
ps. It's good it had a warranty because the new one only lasted 2100 miles before it suffered the same demise. The last one they installed has been performing fine for about 5000 miles now. Good luck with yours.

Could this problem be from the torque converter? It is slipping. It started slipping a little and speeding up, but after about a minute, it would just rev up and not speed up. So I'd let it cool down, and it would grab again and start slipping again.

Danee

Its possible you have signs of a premature PNP failure.. if the flashing arrow up came on (flashing) Are you sure the tranny was slipping?? Or that it was just in Winter mode (3rd Gear) ? Sometimes the cold and /or real wet can put the car into this mode. Restarting the car can reset the sensors but you should check your computer for codes. My car has done that twice over the winter but went away the next next day (and after resetting the ecu) It hasnt came back for the last couple of months. Hopefully for you its corrected itself by now.