As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDED UNDER AMBER ALERT DUE TO GREEN HYDRAULIC SYSTEM LOW PRESSURE MESSAGE. THE SAME MESSAGE CAUSED DIVERSION OF NEXT FLIGHT DUE TO EN ROUTE WEATHER CONDITIONS AND TRADEWINDS AT PLANNED DESTINATION. HYDRAULIC PUMP PRESSURE SWITCH FAILED. REPLACED NR 1 ENGINE DRIVEN HYDRAULIC PUMP PRESSURE SWITCH. RAN BOTH ENGINES FOR SEVERAL MINUTES AND OPERATION OF NR 1 ENGINE HYDRAULIC PUMP WAS NORMAL.