As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING TC 7827300 FOUND NR 2 ENGINE FAULT CODE 73-30312 SHORT TIME FAULT START SIGNAL SWITCH AND ARINC BUS DATA DISAGREE. GROUNDED-YES. REMOVED & REPLACED NR 2 ENGINE EEC, PER B737-800 AMM 73-21-60/401. PERFORMED EEC TEST AFTER INSTALLATION, PER AMM 73-21-00-800. EEC TESTED GOOD AT THIS TIME.