As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GRIOUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW. WHILE IN CRUISE FLIGHT AT FL270 AND 1 HR AFTER TAKEOFF HYDRAULIC GREEN ENGINE #1 PUMP LOW PRESSURE ECAM. FLIGHT CREW ACCOMPLISHED THE ECAM PROCEDURES AND POWER TRANSFER UNIT SUCCESSFULLY POWERED THE GRREEN HYDRAULIC SYSTEM. THE AIRCRAFT LANDED SAFELY AT DFW AND TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE REPLACED LEFT ENGINE HYDRAULIC PUMP PRESSURE SWITCH AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK.