What was found
(CAN) SHORTLY AFTER TAKEOFF FROM POINT A, CREW RECEIVED LT WING ANTI-ICE DUCT WARNING MSG. DISPATCH & MOC WERE CONTACTED & THE QRH WAS FOLLOWED. AFTER WEIGHING, AVAILABLE OPTIONS, DIVERSION INTO POINT B WAS DEEMED SAFEST OPTION AS THE ACFTT WOULD NOT BE ABLE TO FLY IN ICING CONDITIONS. FLIGHT DIVERTED FOR ACFT SWAP & DEPARTED FOR POINT C. MX RECTIFICATION HAD THE LT BLEED AIR LEAK CONTROL UNIT AT FAULT. THE UNIT WAS REPLACED & TESTED IAW AMM 36-21-10. ACFT HOURS 25768:12, CYCLES 20411. THE MFG OF THIS UNIT WAS INDICATED IN THE SYS. HOWEVER, IN THE MFG FIELD ABOVE, THE DROP DOWN DOESN`T OFFER A SELECTION.