I have heard about this mod for some time, but didn't know exactally how to do it. Until tonight... :D
Basically, on a Tacoma TRD, you can only activate & use the E-Locker in 4 Low. As you'd think, it would be nice to use the E-locker in 4 High or even 2 High. I found this link by way of TTORA, so props to them for the info & also to 'Jason' & Offroaders.com for the detailed article on the mod.
Here it is- Full-time E-Locker
Basically, on the drivers side, you unscrew the plastic strip on the floorboard. Once that's off, you unbolt the kick panel & locate the rear diff ECU. Then, after un-bolting the ECU, you cut & splice the Grey wire, then hook it up so it's permanantly grounded.
And that's it... you now have a...