Hi,
So here is an update and how I fixed this issue that prevented me from using about half the nav features on my N4:
if you go into the menu, system, hardware info, and 3d Setup (or something like that), you can see the progress of the system setup. There are progress bars for left, right, distance and 3d orientations. Above the progress bars there is a status section. Here it said "sensor initializing".
Press the line where it says "sensor initializing" a button will appear that says "Clear" (so simple, yet so important). It completely cleared all the progress bars. I was worried because it took a very long time to max out these progress bars but it wasn't a big deal. My next trip I took, the section that said "sensor initializing" now says "3d Hybrid" and all of the features are now working.
If this doesn't work for you, then I would try to get a copy of the CNDV-80MT disks from Pioneer and on some models it will update your firmware. I would do this and then clear the sensor.
I called the Pioneer "tech support" line and they just told me to use a pen and press the reset button on my head unit. If that doesn't work I should remove my head unit and my nav unit and send it to them with no rma number no nothing...the guy didn't even want to be on the phone with me. Wow do these guys suck.
Thanks to everyone here for their help. This forum has been an awesome source of info for me, unlike the pioneer tech support, website or manuals.
cheers