05 Tahoe transfer case problem

[99fxst99]

While driving on the interstate it went into "neutral" and coasted to a stop. Made a whirring noise when attempting to move and rev. Put it in 4AUTO and drove it away just fine. Then 2HI worked again. When I got home I shifted from 2HI to 4AUTO, no problem, back to 2HI and nothing. 4AUTO again worked fine, but there was a slamming noise when it engaged, sitting still, trans in "N".
I am thinking actuator or connection. Thoughts?

BTW, I posted this on the Chevy forum but I bet I get better help here!
<!-- / message -->

[1BadAction]

Actuator or switch. Both known troublemakers.

[wanagofass]

The decoder motor has a sensor in it that's probably going haywire, I think you can get the sensor seperate.

[99fxst99]

OK, back in business. It was the encoder motor. Problem showed up when the tech drove the car, and the scanner confirmed it. Hate to spend the $ right here at Christmas, but at least it's fixed.