As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AIRCRAFT WAS GROUNDED. OUT OF 4,000' GREEN SYSTEM ENGINE DRIVEN PUMP LOW PRESSURE FAILURE. THE FLIGHT RETURNED TO PHL, LANDED UNDER MAX WEIGHT AND WITHOUT FURTHER INCIDENT. REPLACED ENGINE PUMP PRESSURE SWITCH FOR NR 1 ENGINE PER 29-11-17-000-010. ENGINE RUN & LEAK CHECK GOOD.