A couple of months ago the GPS on my AVIC6000 started acting up. It had difficulty locking in on my actual position and it would show me going much faster than my 2012 Jeep Wrangler can go, at one time 135 MPH. Sometimes it will work fine and other times it will show me going across fields or rivers doing in excess of 100 MPH. If there is a road near by it will hop over and show me on it then jump back off road. It started around the time I got an iPhone 7 and started using Car Play. Even if I don't have the iPhone connected it will do this. Sometimes when I connect the phone the phone itself won't show the correct location. I have updated the firmware on the stereo to the latest version. Attached is a link to a video I shot yesterday of it malfunctioning. 

Have you factory reset the unit?

Have you factory reset the unit?

No I haven't 

try checking the GPS menu if it is getting sat

try checking the GPS menu if it is getting sat

I did check it about a month ago and it was getting satellites. You can tell that it is getting GPS signal, it's just that it shows the position off by about a half mile most of the time and the speed will be way off.