TL* THE CONTACT OWNS A 2007 GMC SIERRA. THE CONTACT STATED THAT WHILE DRIVING 55 MPH, THERE WAS SMOKE COMING THROUGH THE VENTS ALONG WITH A BURNING ODOR. THE AIR CONDITIONING UNIT WAS ACTIVATED WHEN THE SMOKE STARTED POURING THROUGH THE VENTS. AS THE AIR CONDITIONER WAS TURNED OFF AND THE SMOKE CEASED. THE AIR CONDITIONER WAS NEVER USED AGAIN. MOST OF THE ELECTRICAL LIGHTS ON THE INSTRUMENT PANEL STARTED TO ILLUMINATE. THE VEHICLE WAS TAKEN TO A MECHANIC WHO STATED THAT THE FAILURE WAS CAUSED BY THE THROTTLE SENSOR OR THE CATALYTIC CONVERTER. NEITHER THE DEALER NOR THE MANUFACTURER WAS NOTIFIED. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS 74,616.