I am currently doing a report on computers and any automotive part. I chose drivetrain. Does anybody here know what is the difference between a computer controlled auto transmission vs. a non-computer controlled one? This is the first place I decided to ask this because I know that a 4L60 in a 93 is not electronically controled but 94s and up are 4L60E and they are computer controlled. So does anyone know the difference in how they work?

 

Basically in a nutshell those that computer controlled have the shifts electronically activated. Those that are non-computer controlled have shifts activated by hydraulic pressure.

 

Non PCM controlled autos like the 700r4 use TV presure verses govenor presure to determine shift points hydraulically, The TH300 used a combination of vacume to the modulator against govenor presure and Detent presure to determine gear and shift point,
Electronically controlled transmissions can do nothing on there own the PCM turn solenoids on and off in certain combinations to direct fluid to the various clutch packs to make different ratos through the planetaries.