As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYS - ATB - LT PACK INOP. PERFORMED FIM 21-51-00, FIG 103. LT PACK CONTROLLER FAULTS COMPRESSOR SENSOR. REPLACED LT PACK COMPRESSOR OUTLET TEMP SENSOR IAW AMM21-51-06-401. TESTS OK. TROUBLESHOOTING WITH FIM21-51-00FIG104B USING APU AIR SHOWED NO FAULTS. TROUBLESHOOTING WITH FIM21-51-00 FIG106 WITH STANDBY CNTL SHOWED NO FAULTS. LT PACK SYS IS OK.