As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, FLIGHT CREW RECEIVED A HYD TEMP HIGH AMBER CAS MESSAGE. THE TEMPERATURE CONTINUED TO CLIMB. ATC DECLARED AN EMERGENCY. AN UNEVENTFUL LANDING WAS ACCOMPLISHED. MAINTENANCE WAS UNABLE TO DUPLICATE THE DISCREPANCY. AS A PRECAUTION AND BASED ON OPERATOR EXPERIENCE, BOTH THE RT HYDRAULIC RESERVOIR AND THE RT HYDRAULIC TEMP TRANSDUCER WERE REPLACED. THERE HAVE BEEN NO REPEAT ISSUES ON SUBSEQUENT FLIGHTS TO DATE.