95 Jeep Grand Cherokee funky problems?

Hello, I have read some of your post and you sound like you could do me some good. I have a 1995 Jeep grand cherokee. Started having some problems. Slight hesitation when I shift from park to drive in the cold mornings, idles steady around 500-700 RPM's, occasionally when I come to a light and stop it will idle roughly down to about 250 RPM's and try to cut off - give her a little gas and she idles fine back up to 500 RPM's, or I can just put it in nuetral and then she still idles at about 500 but its real quiet and smooth but in drive it's a little rough and shakey. Now when I drive she cannot figure out if she wants to go into overdrive or not. Going about 55-60 mph and it will shift overdrive and then back down then overdrive and back down continuously. I replaced the TPS sensor with no prevail. My engine light used to come on randomly but go off once I shut the jeep off and wouldn't come on again. Finally it stayed on and I got the codes 12-32-24-55.I know 12 had to do with the battery being disconnected and 55 mean end of system scan. I am wondering if I need to replaced the MAP sensor or the PCM? I really appreciate any help in the matter and thanks for just reading this long explanation of my problems !