As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL TO EWR - DURING CLIMB, THE CREW RECEIVED A HYDRAULIC SYSTEM 2 FAIL MESSAGE WITH THE SYSTEM 2 HYDRAULIC PRESSURE AT ZERO AND QUANTITY IN THE AMBER RANGE. THE AIRCRAFT RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE PRESSURE LINE FROM THE ENGINE DRIVEN HYDRAULIC PUMP LEAKING. AFTER REPLACING THE PRESSURE LINE AND ENGINE DRIVEN PUMP, THE NR 2 HYDRAULIC SYSTEM OPERATED NORMALLY.