As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT DURING FLIGHT WITH HYDRAULIC SYSTEM ON NO1 RUDDER SYSTEM CAUTION ILLUMINATED ON EICAS. THE MAINTENANCE VENDOR TROUBLESHOT AND DETERMINED THAT THE NO1 RUDDER PRESSURE SWITCH TO BE DEFECTIVE. THE SWITCH WAS REMOVED AND A NEW PRESSURE SWITCH WAS INSTALLED. OPS AND LEAK CHECKS WERE SATISFACTORY. THE AIRCRAFT WAS RETURNED TO SERVICE.