As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 9547 - ATB - THE CREW RETURNED THE AIRCRAFT TO DTW FOLLOWING A "#1 ENGINE ANTI-ICE" MESSAGE. AN EMERGENCY WAS DECLARED WITH ATC ON APPROACH FOR LANDING. CORRECTIVE ACTION: MAINTENANCE REPLACED THE ENGINE ANTI-ICE PRESSURE VALVE AND THE PRESSURE SWITCH. ALSO PERFORMED AN ENGINE PNEUMATIC HEALTH CHECK AND RETURNED TO SERVICE. (LP #9603400)