As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE T/S L/H WTAI FOUND MAINT LIGHT OVERHEAD AND BLEED FAMV L MTX MESSAGE 36-12020 LATCHED. GROUNDED - YES. REMOVED #1 ENGINE FAMV FILTER, NO DEFECTS NOTED. REPLACED FAMV REF B737-9 AMM 36-12-03 AND AMM 36-12-03-000-801. PERFORMED ENGINE ON PNEUMATIC TEST FOR L FAMV, OPS TEST GOOD. MAINT LIGHT EXTINGUISHED AND NO FAULTS.