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 AND THE AIRCRAFT RETURNED TO SFO. YELLOW HYDRAULIC RESERVOIR LOW LEVEL / INDICATES EMPTY ECAM MESSAGE. FLIGHT CREW ACCOMPLISHED ECAM PROCEDURES AND LANDED SAFELY AT SFO WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED # 2 ENGINE HYDRAULIC PRESSURE / SUCTION LINE PER AMM 29-13-49. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.