As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT AT APPROXIMATELY 600 FEET AGL, RECEIVED 'F/CTL ELAC 2 PITCH FAULT' ACCOMPANIED BY UNCOMMANDED 2 TO 3 DEGREE PITCH DOWN INPUTS AND SLUGGISH PITCH RESPONSE. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO BOS AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE TRIMMABLE HORIZONTAL STABILIZER ACTUATOR, OPERATIONAL CHECK OK.