What was found
WHILE PERFORMING OPERATIONAL TEST OF EPSU, RECIEVED FAULT MESSAGES "EPSU BATTERY EMER L, AND EPSU BATTERY AFT L" ON PTP. REPLACED BOTH EPSU BATTERY LEFT (11WL) AND EPSU BATTERY AFT L (13WL) REF AMM 33-51-38-400-002-A. OPS CHECK OK.PARTS USED: 18-3351-3-0001,QTY :1