As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAIN GEAR UNSAFE LIGHT ILLUMINATED WHEN GEAR WAS SELECTED UP. AIRCRAFT RETURNED TO DTW. MAINTENANCE FOUND LEFT WHEEL WELL WITH LARGE ICE ACCUMALATION AROUND GEAR DOOR UPLOCK ACTUATOR. REMOVED ICE AND CLEANED CANNON PLUGS, ALL CHECKS GOOD.