95 Towncar trans problems....help!!!!

So my trans is not shifting correctly!! Sometimes when i drive it shifts down a gear when going 55-60, like it kicks in and out of overdrive or something, and sometimes it shifts into neutral and takes a couple seconds for it to grab the gear again, doing this out of nowhere, not driving it hard or anything!! On some days it drives perfectly fine but others it messes up like that!! Had it took to a tranny shop and they hooked scan tool up to it and said everything was shifting as it should and threw no codes!! But when it shifts right it is very smooth and as it should!! I dont think it is the torque converter because then it would be mesing up all the time, correct? I have heard about the shift module or trans computer going bad, where are those located? Any other possible solutions would be greatly appreciated!!

Sounds like TCC lockup solonid

This is when locks up the converter at highway speeds.

It may be going bad.

Another possibility is the PRNDL switch.

Ok, thanks!! I will try those and see if it helps!! Where are the located?

Transmission Shift Module. It is on the drivers side of the transmission. The linkage goes through it. I replaced mine awhile back for doing the same thing.

Thanks kitt1993, me and my dad will try that and see if that works!!