Eagle Repair: 1991 Summit stuck in gear, eagle summit, car section

Question
Hello, I have a 1991 Eagle Summit with about 117k miles on it. It has been just fine until a few weeks ago when I brought home 8 80ib bags of cement in it, spread out through out the car, it ran fine on the drive home, about 6 miles. The next day the problem started, no take of power, appears to stuck in 2nd gear, once up to speed it never shifts. I have read the thread http://experts.about.com/q/Mitsubishi-Repair-824/1992-Diamante-Trans-stuck.htm and it appears to be an identical problem. I have pulled my ECU and it looks like the big capacitor may have blown as there appears to be a slight amount of leakage from the bottom of the cap but there is what looks like a burn (discoloration) mark on the inside of the metal cover just above where the big cap sits on the board. I still need to pull the TCU for inspection. My main question is, Does the ECU make the TCU do its thing and could both be broken. The car starts just fine and I can rev it in nuetral fine as well. Even with no take off power, there is no skipping or hesitation. Just lack of power as it appears to be stuck in 2nd gear. Thanks for your help.

Answer
They both talk but for the most part when it comes to trans shifting and such your TCU does all the work.

I don't know if you've read my profile but I'm kind of a Mitsu dork myself and have run across a few circuit boards with leaking caps and discoloration (1 this week actually on a 99 GS-T).  I also had a friend with an auto 91-93 talon auto who's TCU quit and stayed in limp-mode.

Chances are you're on the right path with the TCU.  There's actually a post with a few (bad) pics of an ECU that I suspect is bad located here:
http://www.carolinadsm.com/forum/showthread.php?t=20147&page=2

If you'd like to join and post in the "Other car" section we'll see if maybe you can post up some pics and I could check it out.
Doug