As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RECEIVED A-ICE DUCT WARNING MSG IN FLIGHT (LH FUSELAGE) C/W QRH MSG CLEARED. CLEARED AFTER ABOUT 3 MINUTES AFTER SHUTTING OFF 14TH STAGE AIR DIVERTED TO IAD DUE TO ICING ******AIRCRAFT REMOVED FROM SERVICE***************** R&R FWD FUSELAGE AND UNDER CARGO FLOOR SENSING ELEMENT A38WK AND A18WK REF CRJ 200 AMM 36-21-04