Chrysler Repair: 92 Labaron transmission, still limp-in after rebuild, faulty computer, transmission controller

Question
Hello Mr. Finston,

I have a 1992 Lebaron that is in good condition but seems to have a transmission problem.  I took it in and had it hooked up to a computer and it said it needed a new trany.  So, I spent 2 days replacing the transmission and it still doesn't work.  It will only shift into 1st gear.  I thought maybe the transmission computer is the problem so I called around to see if I could locate a used one.  I found one, but they want $400 for it!  That is more than I paid for the car.  If you could give me some ideas, I would appreciate it, otherwise this nice car will be going to the scrapyard.

Thanks for your time,

Derrick Fouks

Answer
Hi Derrick,
If you have any of the "pull-it-yourself" wrecking yards nearby I would go there because the chances are good that they will have cars from the early '90's time frame waiting to have the transmission controller removed and at a much lower cost.
But I would wonder exactly what you did in the 'replacement'? If you got one from a wreck then it might very well also be locked into limp-in mode which is what the original one was probably doing, correct? Actually it is locked in 2nd gear because the trans controller detects an internal problem in the trans and in so-doing is trying to prevent further damage.
Can you tell me what codes were on the original trans readout? There are 4 codes exclusively due to "faulty computer" (11,13,16,17), so if it didn't show one of those I wouldn't spend money to replace it.
Did you rebuild the old trans yourself, buy one from a wreck, have a shop rebuild it (in which case they goofed and should redo the job for free), or exactly what?
I would suggest that the fault codes be read again and this time get the code numbers, names, and what they recommend for repair, and how much $. Then write me back and we can compare what you learn against the '92 A604 shop manual that I have a copy of for cross reference.
Roland