As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENGINE HAS SHORT TERM ENGINE FAULT 77-1113, N2 SPEED SENSOR SIGNALS DISAGREE. ACFT GROUNDED. R & R NR 1 ENG NR 2 SPEED SENSOR IAW MM 77-11-02. PERFORMED EEC BITE TEST IAW MM 71-00-00 AND ENG RUN IAW MM 71-00-00-700-801. SYSTEM OP CHECKED GOOD.