LocalDB doesn't install the necessary drivers to connect to it from an external application. The easiest way to get those drivers is to install
SQL Server Management Studio 2012. Once SSMS is installed, within Access, connect to the ODBC database, create a new machine data source and choose the SQL Server Native Client 11.0
driver. The SQL Server name is (localdb)\maptoolkit. I'll work on creating a TechNet Wiki article with step-by-step directions.
Please remember to click "Mark as Answer" on the post that helps you, and to click
"Unmark as Answer" if a marked post does not actually answer your question. Please
VOTE as HELPFUL if the post helps you. This can be beneficial to other community members reading the thread.