Business & farm

I have a sole proprietorship rental business filing schedule C. I have entered a section 179 deduction for several assets purchased last year and Turbo Tax is NOT warning me I can't use them, even though my business shows a loss and I don't have other income to offset it...  Is this is a turbo tax glitch? Should it be telling me that, I can't use the 179 to make my loss enough to not have to pay capital gains on another sale?  thanks for your time...