Will not shift out of 1st gear

I think what goes wrong with the gearbox is the syncros wear out they're actually the thing that locks your shifter in when you change gears.

Also check your hydraulic fluid sometimes the hydraulic pump can go out to for the clutch

What would make. A Saturn with the automatic transmission it has a brand new transmission in it but it won't shift from first to second gear what would be the problem

That's a good question you might want to take it back to wherever you got the transmission rebuilt at or wherever you bought your new transmission from and especially a course whoever installed the transmission maybe they didn't connect some cables or something that control the selector switch to the solenoid switch that is connected electronically to your throttle position sensor or something. It's some kind of like wire or something if I think right but anyway it's probably a connection issue or it could be a defective transmission I would go back to whoever you bought the transmission from and or whoever installed it and ask them to fix it!

Its ur pcm

I"ve the same problem with sons 2001, runs fine in 2nd but won't shift out. There are SIX solenoids in the transmission, but I'm told that should be the problem and that I don't need a $1300 tranny rebuild. Hoping.

It's a fuse under the hood the needs replaced it's a small red number 10