What was found
DURING CRUISE FLIGHT, THE CREW COULD NOT SHUT OFF FUEL FLOW TO THE UPPER AUX TANK. CREW DIVERTED DUE TO THE MALFUNCTION. FUEL WAS ADDED AND THE MALFUNCTION WAS TRANSFERRED TO DMI. TRAVEL WAS RESUMED. ONCE IN DESTINATION, THE AUX FILL VALVE ACTUATOR WAS REPLACED, DMI WAS CLEARED, AND THE OPS CHECK WAS NORMAL. ACFT HAS RESUMED FLYING WITHOUT INCIDENT.