Hyundai Repair: rough shifting from 2nd to 3rd, hyundai santa fe, bumper to bumper warranty

Question
I have a 2005 hyundai Santa Fe with a 3.5 engine, for the past few weeks it has been shifting very rough, but only from 2nd to 3rd. My check engine light has not come on and no codes were found with the code reader. I am worried that it could be my transmission, but I would like to know at the least what the problem could be before I take it in.

Answer
Your problem could be caused by improper fluid level or perhaps by the dealer performing a relearn procedure on the transmission control module (TCM) adaptive values, but most likely there's a serious problem in the transmission requiring overhaul or replacement.  If you're the original owner and this vehicle has less than 100,000 miles (or you're still within the 5 year/60,000 mile bumper-to-bumper warranty), it'll be to your advantage to go to the dealer to have this investigated.  If it is in the transmission, that should be covered under your warranty.