What was found
AIR INTERRUPT, RETURNED & EMER DECLARED. LANDING UNEVENTFUL & ACFT WAS OVERWEIGHT. FLIGHT INTERRUPTION DUE TO FLIGHT CONTROL CAUTION EICAS MSG CAME ON AT 1500 FT. CHECKED WIRING & FOUND ELECTRICAL CONNECTOR D4310P LOOSE, FROM ACE L1 TO LT OTBD ELEVATOR PCU, MAT MX MSG 27-11111. RETIGHTENED ELEC CONNECTOR. CHECKED FLIGHT CONTROL SYSTEM OPERATIONS IAW AMM & FOUND OK. FLIGHT CONTROL MSG CLEARED.