front end engaging without me shifting?

I have a 2001 tacoma with a 3" bodylift, and while driving the front end sounds like it is trying to engage. The light on the dash board comes on but the trasfer case is in 2wd. has anyone had this problem, or know of this problem.

that info is great, but my front add system is locking in the hubs while transfer case is still in 2wd, while I'm just cruising down the road.

Check everything in that post that may apply to your problem, which is most of it. Something in the ADD system is malfunctioning, and that is how you test them.