In the HP-1 (I know, different scanner) "Auto Locate" is a method of establishing a "rough" location by an analysis of the radio channels/frequencies that are presently in the vicinity of the radio. I've only used it twice. Once when I first got the radio (returned a "co-ordinates" result about 50 miles away), and once today (returned MARICOPA COUNTY) to try and answer your question. With the HP-1, "Auto Locate" has nothing to do with the GPS options. GPS options should give your location within a hundred feet or so.
This post is probably not helpful as the new scanners may not work like the HP-1. Also, only "Auto Locating" twice, three years apart, I may be just blowing hot air, lol.