The Ohio school district return is not automatically prepared by TurboTax (TT). You have to initiate it*. So, if you do not have a form SD100 on your list of Ohio forms, you did not file a school district income tax (SDIT) form. Even if you do have an SD100, be aware that the School District return is usually e-filed with the state return, but there are exceptions. Read the "filing instructions" that TurboTax prepares, They will tell you if the SD100 was e-filed or if you should have mailed it.
At this point, you may actually find it easier to do the form by hand. Get the form at http://www.tax.ohio.gov/Forms.aspx. Even if you decide to use TT, I suggest you review the form first to help understand what the TT interview is going for.
To verify that you live in a school district with an income tax enter your address at:
* At the screen, in the Ohio program, titled "A few things before we wrap up your state taxes", scroll down to School District taxes. If you instead reach the "Your 2015 Ohio Taxes are ready for us to check" screen, scroll down to Other Situations, then scroll down to School District taxes.