What was found
A LEFT HAND AIR CONDITIONING PACK OVERHEAT WARNING MESSAGE ILLUMINATED, DURING THE TAXI OUT FOR TAKEOFF. THE AIRCRAFT RETURNED TO THE GATE. OUTSTATION MAINTENANCE INSPECTED, AND APPROVED THE AIRCRAFT FOR A FERRY FLIGHT TO PIT. THE FERRY FLIGHT TOOK PLACE WITHOUT ANY PROBLEMS. PIT MAINTENANCE INSPECTED AND REPLACED THE LEFT HAND NACA DUCT CHECK VALVE, IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 21-51-24. OPERATIONAL CHECKS WERE COMPLETED, AND THE AIRCRAFT WAS RETURNED TO SERVICE.