Determine if you e-filed a City of Detroit return by viewing your printed forms. The City of Detroit tax return is e-filed with the State of Michigan forms when chosen to in TurboTax. When reviewing your printed forms, look for either Form 5118 (City of Detroit Resident) or Form 5119 (City of Detroit Non Resident). Once reviewing those forms you can determine what was filed.
When generating the forms in TurboTax, you would have had to select that you needed a City of Detroit return, and it would have had you choose whether you were a resident, non resident or part year resident. If you don't recall completing this area of TurboTax, a City of Detroit return may not have been generated.
You can choose to file the City of Detroit non resident form manually by using the forms in this link below:
http://www.michigan.gov/documents/taxes/5119_609388_7.pdf
How to print return:
https://ttlc.intuit.com/replies/3301609