As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 3440, RUDDER LIMITER LIGHT ILLUMINATED INFLIGHT. AIR RETURN TO DTW. MAINTENANCE REMOVED AND REPLACED ADAU ALL CHECKS GOOD IAW RJ-85 MM CH 34. S/N OFF 644/WDFD/98, P/N OFF WDFD-ATEL-1025-000, S/N ON 561WDFD97, P/N ON HC396HO485-008.