As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN FOR ANTI-ICE DUCT WARNING MSG INFLIGHT CLIMBOUT OF DTW WITH WING & COWL ANTI ICE ON. QRH COMPLETED MSG WENT OUT AFTER 14TH STAGE BLEEDS TURNED OFF MSG CAME BACK WHEN 14TH STAGE BLEEDS AND WING & COWL ICE TURNED BACK ON COMING BACK TO DTW IN ICING CONDITIONS. REMOVED AND REPLACED A 42WK SENSING ELEMENT IAW AMM 36-21-04.