What was found
DURING SERVICE CHECK, FOUND AFT L (13WL) EPCU BATTERY FAILED, REPLACED AFT L(13WL) BATTERY
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
DURING SERVICE CHECK, FOUND AFT L (13WL) EPCU BATTERY FAILED, REPLACED AFT L(13WL) BATTERY