2001 Santa Fe acting up

So I have a 2001 Santa Fe. Today it was 100
degrees out and I was driving about 80mph down
the highway when all of a sudden the car jerks and
the check engine light turns on. I got to my exit and
had to stop. When I tried to get the car moving
again it was stuck in 2nd. Since it has an automatic/
manual transmission I tried shifting it on its own. It
wouldn't go into 1st or 4th and would down shift on
its own like it's supposed to. I got to where I was
going parked for about fifteen minutes than tried to
run the car again, after checking all my fluids. The
transmission was fine. It got home and everything.
Check engine light is still on. Any ideas? Break light
and battery light have been on since yesterday off
and on, as well.