Chrysler Repair: 1995 Dodge Stratus ES-V6, speed sensors, dodge stratus

Question
I had problems with transmission going into limp mode and sometimes the speedometer would not work.  Took it to Autozone for free code readout and they could not get any communication with computer.  Tried autokey sequence and only got codes 12,32,55.  I know 32 is EGR and need to fix that but don't think it is related to trans issue.

So, I replaced input output sensors on transmission since they were a cheap starting point and I read that they could be a symptom of no speedometer.  After sensor replacement, there was initially no change (still limp mode).  But, then I took it back to Autozone to try codes again and same thing no communication.  BUT, I asked him to reset computer anyway.  He did this and bravo!  When I left the Autozone, transmission shifted perfectly.  Drove car for 3 days in various traffic conditions and trans worked perfectly.  Then, after third day it suddenly started going into limp mode again.  Still get no communication when checking codes at Autozone, but key method still gives 12,32,55 and SOMETIMES key method will give a 66 code (TCM not sensed by PCM).  Still get no speedometer occasionally as well. Car is too old to spend too much on it (150k miles), but it runs great except for limp mode issue!  Would it be worth my trouble to replace TCM, or do I need to take this to a dealer?  I would appreciate your opinion.  

BTW, I disconnected battery and removed and reseated all plugs for TCM, PCM, and input and output speed sensors.  No changes after that.  Also note that trans was rebuilt at 95K by a former Chrylser trany mechanic.  Car now has 150k.

Answer
Hi Glenn,
Thanks for the detailed history. I would pursue the 66 code by checking the data bus wires for continuity between the transmission/body/powertrain computers. Shake the harnesses as you do these checks in the hope of finding a poor connection. If none is found, then the suggested solution in the powertrain manual is to replace the TCM. You should be able to get a used one at a wrecking yard, ideally from the same year/powertrain/model.
Bus -  white/dark green  
   +  violet/brown

Check tcm 43 to    bcm 6
          4 to  (black)14
                 plug)
Check bcm  5 to pcm 59
  (black  13 to    60
    plug)
The wiring is a bit more complex than shown above in that the bcm has
several connections to the data bus, so if you don't find a problem let me know and I can xerox and postal mail the diagrams to you.
Roland