As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT GEAR RED LIGHT REMAINED ILLUMINATED AFTER GEAR RETRACTION. CYCLED GEAR LIGHT REMAINED ON AFTER RETRACTION. AIR RETURN TO DTW. MAINTENANCE JACKED A/C AND SWUNG GEAR NUMEROUS TIMES COULD NOT DUPLICATE ORIGINAL DISCREPANCY. CHANGED RELAY GF2 FOR PRECAUTIONARY MEASURES WITH SUBSEQUENT SWINGS. ALL CHECKS GOOD AT THIS TIME. PN MS27400-17 ALL IAW AVRO MM CHAP 12 & 32.