As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED LEFT TANK FUEL IMBALANCE ON CLIMBOUT. IMBALANCE WORSENED WHEN USING CENTER TANK. RAN QRH CHECKLIST AND SHUTDOWN LEFT ENGINE (SINGLE ENGINE TIME 15 MINS). LEFT QUANTITY STOPPED DECREASING WITH ENGINE SHUTDOWN. EMERGENCY DECLARED FLIGHT RETURNED & LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED CROSSFEED VALVE ACTUATOR. SYSTEM GROUND CHECKED NORMAL.