Do all PreRunners have LRD and Hill Assist?

So, I just bought a used 06 PreRunner 4 cyl, 5 speed standard. This is my first non-4WD, non-automatic truck, so I'm unfamiliar with this set-up.

One of the rectangular black plugs to the lower left of the steering wheel is missing. I wasn't worried about it, and figured I find a replacement plug in a junkyard or stick a foglight switch in there.

But then I remembered that PreRunners are supposed to have LRDs, aren't they? And what about the hill assist thing? Now, I'm wondering what was originally in that slot? And how worried should I be that it's not there?

 

Locking rear diff is an option included in the TRD off road package and has nothing to do with being a prerunner. Down hill assist is also an option and im not sure what years its in and what packages. I do not have it.

 

Hill Assist is only available on 4x4 models, and if I remember correctly, only on 4x4 v6 models. Also, The only PreRunners that have the E-Locker is the TRD Off-Road PreRunner.

 

Somewhere someone asked about what all the blanks were for, search for it and it may clue you in on what is missing...

However, for the 4 cyl PreRunner, all those were blank (I have an '05 SR5). Only V6s got to add the TRD package that includes fogs, inverter, locking diff, clutch start cancel, etc as standard features. Chances are a previous owner installed something after market and took it off before selling it to you.