As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING T/C 78273000 FAULT CODE APPEARED ON NR 2 ENGINE, FAULT CODE 73-31162, THE MECHANICAL OVERSPEED PROTECTION SIGNAL IS OUT OF RANGE, LONG TIME. MUST BE CORRECTED IN 450 HRS. GROUNDED - YES. REMOVED AND REPLACED HMU ON NR 2 ENGINE IAW T/C'S N8473000 AND N8473001. RAN ENGINE, NO LEAKS NOTED AND GROUND VERIFICATION CONFIRMED NO FAULTS NOTED.