Why is my Nuvi 50 doing this?!

 

Once in a while all or part of the screen will switch to a topographical view for anywhere from 1 second to maybe a minute or two, then will switch back to normal view. It doesn't seem to do this in cities or at lower speed, only when on the freeway at higher speeds.

Is

Is the Nuvi zooming in or out when this happens? Most newer Nuvi's (not sure about the 50) have a DEM map that provides 3D representation of a terrain surface's when the road map is displayed on the map screen.

I find that this DEM view is most noticeable when outside populated areas and when the map is zoomed out fairly far, which would be the case when your travelling at speed on the highway.

When the Nuvi zooms out as you speed up is when you may notice the change in map detail the most.

--
Nuvi 350, 760, 1695LM, 3790LMT, 2460LMT, 3597LMTHD, DriveLuxe 50LMTHD, DriveSmart 61, Garmin Backup Camera 40 and TomTom XXL540s.

Zoooooming

I also find my 3790 gives me a terrain view, but it only seems to happen when I am on a scheduled route and it seems to be more in unpopulated mountainous areas.

--
Nuvi 350 long gone, Nuvi 855LMT, Nuvi 2797LMT, SmartDrive 50 LMT-HD, 3790LMT now my daughters. Using Windows 10. DashCam A108C with GPS.