As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4243 THE CREW DECLARED AN EMERGENCY ON APPROACH TO ORD FOR A MAIN PITCH TRIM FAIL. THE STANDBY WAS OPERABLE. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE HORIZONTAL STABILIZER CONTROL UNIT IAW EMB 145 AMM 27-40-01. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.