TL* THE CONTACTS OWNS A 2003 CHEVROLET SILVERADO 1500 HD. THE CONTACT STATED THAT SMOKE WAS EMITTING OUT OF THE CENTER OF THE AIR VENT DUCT. THE VEHICLE WAS TAKEN TO A DEALER. THE TECHNICIAN WAS UNABLE TO DIAGNOSE THE FAILURE. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 68,403 AND THE CURRENT MILEAGE WAS 150,000.