I did a ton of reading and learned how a torque converter works now, but now I don't get how the toggle switch works for locking it up. I also read it can be programmed into the computer at a certain RPM in a certain gear, how does all that work?

I'm looking at getting a TC for my 4L60E, but also want the driveability at higher speeds.

 

Its the vss,tps and prom values thats engage or release lock up.
you can get http://www.supportfitness.com/mark/t...ownloadApp.htm
and the xdf with your bin to the car and look at it .
If you have tuner pro you can see all the values in the bin and
understand it better.