PLEASE HELP,

I'm having problems with the transmission in my MR2 turbo. My tranny can only shift into 1st and 2nd gear. When I shift into 3rd, 4th, or 5th the gear stays in 2nd. I'm thinking one of the linkage cable's is loose, What else could it possibly be? Also what is the tranny code, is it an S54 or an E153?

Thanks