As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXCESSIVE VIBRATION WAS COMING FROM NOSE GEAR AREA AFTER TAKEOFF. FLIGHT RETURNED TO DTW AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND FOUND BOTH NOSE GEAR DOOR UP AND LOCKED. NO DISCREPANCIES COULD BE FOUND. AIRCRAFT RETURNED TO SERVICE.