My 95 XJ with an auto trans cant be driven manually in 2nd gear. If you look at the gear selector and shift it all the way down where it reads 1-2, it only stays in low 1 and wont shift into 2nd. one click up and it is in drive (3rd). Is this the way they are? If so, why even have the "2" in the 1-2 selector? When towing, it would be nice to keep it in 2nd to climb a steep hill and more importantly, keep it in 2nd to come down a steep hill.

 

To lock 2nd you have to do a switch mod with wiring to the Trans control module. If you are starting in 1-2 and shift to 3, below a certain speed it will stay in 2nd, but I understand the frustration climbing hills with it because driving in the mountains up long hills in 3rd really sucks.
If you are doing at least 30mph, you can drop it into 1-2 and it will go to 2nd, but if the kickdown cable is adjusted wrong you will get some nice whiplash when it drops into 1st at 35mph (like mine before I fixed it)

 

It should shift from 1st to 2nd when accelerating from a stop and the selector is in the 1/2 position.....ours does.

 

It will shift from 1-2 (when in that position) at about 4500 rpm, TCU connected or not.