As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN REPORTED GREEN SYSTEM LOSS IN CRUISE. FLUID QUANTITY WENT TO "0". AIRCRAFT RETURNED TO FIELD AND WAS TOWED TO GATE DUE TO LACK OF NOSEWHEEL STEERING. MAINTENANCE FOUND PTU CASE DRAIN LEAKING. REMOVED AND REPLACED POWER TRANSFER UNIT IAW AIRBUS MAINTENANCE MANUAL 29-23-41-400.