We have encountered a few newer Model Subaru Outbacks (2010 to 2014) with a check device error message when a smart phone, tablet etc is plugged in. This would include my 2012 Subaru Outback.
Subaru just a couple of months ago put out a TSB ( Technical Service Bulletin) to help explain this. There is no fix mind you, just an understanding of how heat affects the low voltage systems in particular in a modern vehicle. Essentially what occurs is that in warm weather situations the increase in heat will cause a decrease in the supplied voltage to a device through the USB port the system senses the decrease in voltage and displays the error.
Thanks for reading
-Justin
Thanks for this, it has happened every summer on our 2010 Outback, and the Dealer never had any idea of what we were talking about.
Love your blog by the way, have learned a lot!
Robert H