As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING TC 78273000 FOUND FAULT 73-20021 ON #1 ENGINE. SHORT TIME FAULT INTERNAL EEC FAULT. DEFERRED PER TC 78273000. GROUNDED - YES. ACCOMPLISHED T/C 787273000 #1 ENGINE HAS NO RECENT FAULTS AND NOTHING IN FAULT HISTORY. ACCOMPLISHED EEC BITE PER B737-900 FIM 73-00 TASK 801 AND FIM 73-21 TASK 801 INITIAL EVALUATION AND PER FIM ALSO EEC TEST PER B737-900 AMM 73-21-00-700-804-F00 NO FAULTS NOTED.