What was found
(CAN) DURING THE CRUISE THE CREW REPORTED A WING LEAK/ANTI ICE FAULT. AFTER DISCUSSION WITH MAINTENANCE THE FLIGHT RETURNED DUE TO POSSIBLE ICING CONDITIONS AT DESTINATION LOOSE CONNECTOR PLUG ON SLAT 2 HARNESS FOUND AND RETIGHTENED. CUSTOM I/O MODULE 2, REPLACED DUE TO FAILED SELF TEST IAW AMM 31-41-07/401. CHECKED SERVICEABLE. WING ANTI-ICE TEST CARRIED OUT IAW AMM 30-11-00, PB501, NO FAULTS.