Help! At light keeps appearing!
 

I recently had a code for a TCM problem, so I had it replaced. After that the AT light went away and the car was driving perfectly fine for a couple of months. Now the AT light comes back randomly while I'm driving. The car drives perfectly fine but out of random pops into "AT mode" and the car drives at a reduced speed. Accelerating doesn't really move the car, it kind of just stays idling in drive. I took the car to the mazda dealer and they were useless they told me they do not know what is causing the light to come on because there is no code. IF YOU HAVE ANY IDEA OF WHAT THE PROBLEM IS PLEASE LET ME KNOW IT'LL HELP ALOT! Thanks!
ALSO, If I put the car in sport mode and manually shift the gears the AT light takes longer to pop up.

2006 Mazda3 s 2.3L (Hatchback 5-door)