As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ACCOMPLISHMENT OF T/C 78273000, NR 1 ENGINE HAS FAULT MSG 75-20391, VSV POSITION SIGNAL IS OUT OF RANGE. LONG TERM FAULT. ACFT GROUNDED. INTERROGATED THE FMC CDU FOR ENGINE FAULTS REF T/C 78273000 AND FOUND MESSAGE 75-20391, NO LONGER ACTIVE LAST 10 FLIGHT LEGS IN HISTORY.