As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING EEC BITE TEST FOR #1 ENGINE FOUND FAULT MSG NBR 73-31371 (UPPER EGT SECTORS READING HIGH). REF T/C # 78273000. GROUNDED - YES. C/W B737-900 FIM 73-11 TASK 801. T49.5 PARAMETERS WERE WITHIN RANGE. EEC BITE TEST DID NOT SHOW FAULT IN FLIGHT LEG ZERO. NO FURTHER DISCREPANCIES NOTED.