2000 elantra auto tranny problem
 

I've seen similar posts here, but my 2000 elantra is having trouble shifting into 4th. Codes are P0734, P1624, and P0713. The first one is new, the other 2 were there when I got the car 18 months ago. All 3 have this in common: "possible open or short circuit condition". Is it likely that there's a problem in the wiring harness or is it more probable that the tranny is shot? Thanks!