As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT FAILED TO SHIFT FROM GROUND MODE TO FLIGHT MODE AFTER TAKEOFF. FLIGHT RETURNED TO DTW AND LANDED WITHOUT INCIDENT. SERVICED NOSE LANDING GEAR STRUT TO PROPER LEVELS OF FLUID AND NITROGEN. OPERATIONAL CHECK NORMAL AND AIRCRAFT RETURNED TO SERVICE.