As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOTS NOTED AUTOPILOT WOULD NOT TRIM AIRCRAFT. PILOT DE-SELECTED AUTOPILOT AND TRIM FUNCTIONED CORRECTLY IN MANUAL MODE 'NORMAL' POSITION, HOWEVER, WOULD NOT FUNCTION WHEN 'EMERGENCY' TRIM WAS SELECTED. ON THE GROUND, BOTH 'NORMAL' AND 'EMERGENCY' POSITIONS WORKED. AUTOPILOT OUTPUTS TESTED OK. PITCH ACTUATOR REPLACED. AIRCRAFT FUNCTIONED NORMALLY. SPECIFIC FAILURE OR CAUSE UNKNOWN AT THIS TIME.