Shift from drive to reverse reverse does not work

I suspect you have a shift cable or range sensor issue. Basically when they are out of adjustment, they don't let you get into the gear properly and it won't engage.

Let's run through this info and go from there. The first is a TSB that talks about replacing the cable which you may have to do and the adjustment of the TRS. That requires a special tool that most all parts stores offer pretty cheap.

Let me know what questions you have. Thanks