As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED STAB TRIM CAUTION MESSAGE AND RUNAWAY DURING CLIMB. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT, REMOVED AND REPLACED HSTCU (HORIZONTAL STABILIZER TRIM CONTROL UNIT), CLEANED MACH TRIM SWITCH AND PERFORMED CHECKS USING AIRCRAFT MAINTENANCE MANUALS. AIRCRAFT RELEASED FOR SERVICE.