As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING T/C # 78273000 FOUND SHORT TIME FAULT MSG NBR: 73-20011 INTERNAL EEC FAULT ON # 1 ENGINE. GROUNDED - YES. ACCOMPLISHED B737-900 FIM 73-21 TASK 801 FOR #1 ENGINE EEC. REINSTALLED EEC SOFTWARE PER B737-900 AMM 73-21-60-470-801-F00. ALL TEST PASSED. GROUND VERIFICATION SUCCESSFUL. NO FAULTS FOUND.