As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW RECEIVED AN, ANTI-ICE DUCT, WARNING MESSAGE AT APPROXIMATELY 4000 MSL. DURING CLIMB IN ICING CONDITIONS WITH WING AND COWL ANTI-ICE ON. AFTER APPROXIMATELY 30 SEC., THE ANTI-ICE DUCT CAUTION MESSAGE APPEARED AND THE WARNING MESSAGE EXTINGUISHED. CREW COMPLIED WITH THE QRH. AN EMERGENCY WAS DECLARED AS A PRECAUTION AND THE ACFT RETURNED TO ORIGIN WITH AN UNEVENTFUL LANDING. FIRE LOOPS REPOSITIONED.