As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT RETURNED TO PHL ON ACCOUNT OF NUMBER TWO ENGINE BLEED AND PACK FAILED. AN EMERGENCY WAS DECLARED. MAINTENANCE REPLACED SENSE LINE BETWEEN BLEED PRESSURE REGULATOR VALVE AND PYLON INTERFACE IAW AMM TASK 36-11-49. ENGINE 2 BLEED SYSTEM CHECKS NORMAL IAW AMM 36-11-00-710-003A.