As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO YELLOW HYDRAULIC SYSTEM RESERVOIR OVERHEAT MESSAGE. FLIGHT CREW FOLLOWED ECAM PROCEDURES AND TURNED OFF THE YELLOW HYDRAULIC SYSTEM. THE AIRCRAFT LANDED SAFELY AT DFW WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE YELLOW HYDRAULIC SYSTEM WAS OVERSERVICED AND SERVICED THE SYTEM PER AMM 12-29-29. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.