As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING TASK CARD SBCFM56-7B-73-0233-1, NEW SOFTWARE WAS UNABLE TO LOAD USING MULTIPLE TECHSAT LOADERS ON #2 ENGINE. GROUNDED - YES. REMOVED AND REPLACED EEC ON #2 ENGINE REF B737-900 AMM 73-21-60. CONFIRMED NEWEST SOFTWARE ALREADY LOADED ON NEW EEC, PART TRANSACTION LISTED ON TASK CARD SBCFM56-7B-73-0233-1. PERFORMED FADEC SYSTEM TEST REF AMM 73-21-00-802-F00, ALL TESTS PASS, ETOPS GROUND VERIFICATION SUCCESSFUL.