You should do the non-resident Indiana return first in TurboTax.
You will claim the income you earned there and you will owe tax.
Next you will file your resident Illinois return and claim all your income. You will be taxed on all the income but also get a credit for the Indiana tax.
You must do the Indiana return first so TurboTax knows what to put on the Illinois return as a credit.
Make sure that when you entered the W-2 you selected the correct state for Box 15. Illinois is right above Indiana on the drop-down list, verify the right one was entered.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"