As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FLT 729 EN-ROUTE LHR TO PHL. APPROXIMATELY ONE HOUR UNTIL LANDING, THE NUMBER FOUR TIRE PRESSURE 180 PSI GENERATED ON ECAM. THE CREW FOLLOWED QRH PROCEDURES, AND DECLARED AN EMERGENCY AS A PRECAUTION. THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. THE NUMBER FOUR MAIN LANDING GEAR TIRE WAS BELOW RE-INFLATION LIMIT. REMOVED AND REPLACED NUMBER FOUR MAIN WHEEL ASSEMBLY.