As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN FLIGHT, THE ENGINE FUEL FILTER BYPASS CAUTION LIGHT CAME ON. THE ACFT RETURNED TO BASE. THE HIGH PRESSURE FUEL FILTER WAS INSPECTED AND FOUND DIRTY. FUEL FILTER WAS REPLACED IAW THE ACFT MM PROCEDURES, THE ENGINE WAS GROUND RUN, NO CAUTION LIGHT INDICATION NOTED. THE FILTER HOUSING AREA WAS INSPECTED FOR LEAKAGE, WITH NONE FOUND. THE ACFT WAS DEEMED AIRWORTHY AND RETURNED TO SERVICE.