As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHENEVER THE TAIL DE-ICE IS SELECTED, THE AIRFOIL ICE PROTECTION PRESSURE ABNORMAL LIGHT ILLUMINATES. FOLLOWED COCKPIT OPERATING MANUAL PROCEDURES AND RETURNED TO DTW. FLIGHT LANDED WITHOUT INCIDENT. MAINTENANCE CHANGED TAIL DE-ICE TIMER, OPERATIONAL CHECK OK.