As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB THE LT ENG FUEL FILTER BYPASS INDICATION CAME ON. EMER DECLARED FLIGHT RETURNED & LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. R & R LT ENG FUEL FILTER & FUEL FILTER BYPASS SWITCH. SYS GND CHECKED NORMAL OPERATION CLOSED.