I hate to be the bearer of bad news but it looks like 2G support for the Garmin GTU 10 will end on 12/31/15. Take a look at this review from Amazon for more details.
https://www.amazon.com/gp/customer-.../ref=cm_cr_pr_viewpnt?ie=UTF8&ASIN=B004HFRA7A
https://www.amazon.com/gp/customer-.../ref=cm_cr_pr_viewpnt?ie=UTF8&ASIN=B004HFRA7A