As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW HEARD LOUD THUMPING ON LEFT SIDE OF AIRCRAFT, AND HAD L/E SLAT DISAGREE LIGHT ILLUMINATE. DIVERTED TO SLC. NUISANCE EICAS MESSAGE GENERATED BY PROXIMITY SWITCH SYSTEM. THERE IS NO HISTORY OF SLAT POSITION PROBLEMS ON THIS AIRCRAFT. PERFORMED PSEU BITE CHECK ON ALL LEADING EDGE SLAT PROXIMITY SWITCHES PER APPLICABLE MAINTENANCE MANUAL AND ALL CHECKED OK. OPERATIONALLY CHECKED L/E SLATS PER APPLICABLE MAINTENANCE MANUAL AND ALL OPS CHECKED OK.