Hyundai Repair: 2002 Hyundai Accent transmission, hyundai accent, warranty plan

Question
Hi! My son's 2002 Hyndai Accent's check engine light came on when he was making a trip from Houston to Dallas. He went to the dealer and they couldn't find anything wrong and told him that maybe he needs to change the transmission fluid. He didn't have the money to do that right then so they have not been driving the car. He took it back yesterday and they told him that his transmission fluid was burnt. (We're wondering why they didn't pick up on that the first trip) We thought it would have been covered under warranty, but they asked if he had changed the transmission fluid since he purchased the vehicle. He has never changed it. Was that requirement under Hyndai's warranty plan to have to change it at a certain mileage? His vehicle has 60,000. Thanks for your help.

Answer
If the check engine lamp came on, there was a problem.  The fact that this lamp was on means that there was a trouble code stored in the engine or transmission computer.  To be able to give you assistance as to the nature of the problem, I'll need to know the code(s).  

Since the dealer recommended changing the transmission fluid, it was probably a transmission trouble code.  The dealer probably noted on the original visit that the fluid was burnt, but didn't mention that because they already had another reason to recommend changing it.  If the transmission fluid needs to be changed, it doesn't really matter how many reasons there are to change it.

The requirement in Hyundai's owner's manual is 105k miles, but it also has regular intervals of inspect and replace if necessary.  So, if the fluid is burnt, or excessively dirty, then you'll need to change it, whenever that is.

I'm curious to know what the trouble code was.  If you can find out, let me know.  I'll tell you what it means.  Replacing transmission fluid rarely (but sometimes) fixes transmission problems.