As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING TC 78273000, TO INTERROGATE THE FMC CDU FOR ENGINE FAULTS, FOUND TWO SHORT TERM FAULTS FOR THE INTERNAL EEC FAULT (FC 73-10011, 73-10021) NR 1 ENGINE. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 ENGINE EEC IAW AMM 73-21-60. PERFORMED TESTS LISTED IN POWER PLANT TEST TABLE AMM 71-00-00-800-811-F00. FADEC SYSTEM TEST AMM 73-21-00-700-802-F00. VERIFIED SW INSTALLED CORRECT AND ALL TESTS PASSED. PERFORMED ENGINE IDLE RUN AND NO FMC CDU ENGINE FAULTS NOTED.