As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR INTRANSIT LIGHT REMAINS ILLUMINATED AFTER SELECTING GEAR UP. AIR RETURN TO DTW. MAINTENANCE PERFORMED TROUBLESHOOTING OF LANDING GEAR EXTENSION AND RETRACTION SYSTEMS. FOUND RT MLG UPLOCK SWITCH OUT OF ADJUSTMENT. ADJUSTED RT UPLOCK SWITCH SF340MM 32-61-15-2. PERFORMED FUNCTIONAL TEST OF EXTENSION AND RETRACTION SYSTEM. ALL CHECKS GOOD.