I'm newly registered but have lurked for a bit - I love the articles and your search function works well! Kudos.
My Sis's B/F has a '95 T-bird - looks like a mod motor with an electronically actuated trans (with a 4R trans, I think. The car is stock).
I'll provide what I know and try to acquire answers to questions you have.
The car today (out of the blue) lost reverse and neutral. That is, both of those gears now are forward gears
, acting as if in drive (the car started rolling forward uphill).
He says Drive seems to work but I don't know if he has all speeds, and if 2 and 1 positions work.
He said the fluid level is ok, but I'll double check that.
I had him try to start it in Reverse and Drive and it wont (I was thinking this might provide a clue about the MLPS). Back-up lights work in Reverse (and only reverse).
I'll post more info as I can get it, but I was hoping all of you wise folks might have some suggestions, pointed questions that I can ask, and diagnostics for me to do.
I admit to not knowing much about his car (I have a '94 Mustang GT and an 88 GT vert, etc) so feel free to treat me like the idiot that I am.
Thank you for any suggestions you might have (I searched based on the symptoms as best I could, but most folks with a similar issue had done a valvebody modification incorrectly, it seemed).