2003 dodge neon sxt with 104,000m recently new trans, check engine light is on now running hot?

I recently had a new transm put in because one day my car would not go while driving and the next day it was fine. I was told it was my trans so I had it fixed. Check engind light on today, no unusual noises, running hotter than normal though. Recently , last week had an oil change, tune up.