a/t computer ware is it?

[1991eagletalon]

please help im going crazy! i have a 1991 eagle tsi with a automatic trans... it is stuck in third gear for some reason it was not slipping or anything bad when i park it ... some one said that it's possiable that the trans computer is bad i didnt know there was a seperate computer for the transmission... some one called it (limp mode) please please help if you can thanks ....

 

[98TalonTSi]

It should be laying on the floor behind the center console...behind the ECU