As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED T/O YAW DAMPER ENGAGE RUDDER RT DEFLECTION. WHEN TRIM KNOB WAS ACTIVATED, EXTREME LT WAS OPERATED. THE ACFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINT REMOVED AND REPLACED THE TRIM CONTROL MODULE, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE ACFT WAS APPROVED FOR RETURN TO SERVICE.