As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS AT CRUISE FLIGHT JUST BEFORE TOP OF DESCENT, APPR PUSH BUTTON ARMED ITSELF W/O ANY CREW INTERACTION RECEIVED AUDIO TRIPLE-CLICK,THEN A/C REVERTED TO V/S. PFD WAS FLASHING "ILS" IN AMBER. MAINTENANCE RESET FCU 1&2. SUCCESSFUL AFS TEST IAW AMM 22-96-00. SUCCESSFUL LAND CAT 3 CAPABILITY TEST IAW AMM 22-97-00. NO FAULTS FOUND.