ENGINE COMPARTMENT FIRE

THE OFFICE OF DEFECTS INVESTIGATION (ODI) IS AWARE OF 7 SUBJECT VEHICLES THAT HAVE ALLEGEDLY EXPERIENCED ENGINE COMPARTMENT FIRES ORIGINATING AT THE COIL-ON-PLUG (COP) IGNITION COIL ASSEMBLY AND 28 ALLEGED NON-FIRE THERMAL EVENTS RESULTING IN DAMAGE LIMITED TO THE SUBJECT COMPONENT AND ASSOCIATED WIRING. ALL REPORTED INCIDENTS OCCURRED WHILE THE VEHICLES WERE ATTENDED AND IN ALL BUT ONE CASE THE SUBJECT VEHICLES WERE REPAIRED AND RETURNED TO SERVICE AFTER THE INCIDENT INVOLVING THE ALLEGED DEFECT. ACCORDING TO GENERAL MOTORS (GM), A CERAMIC CAPACITOR USED IN THE ELECTROMAGNETIC NOISE FILTER CIRCUIT INSIDE THE SUBJECT COMPONENT MAY HAVE BEEN DAMAGED DURING THE MANUFACTURING PROCESS. A FRACTURE INSIDE THE CAPACITOR MAY, DEPENDING ON ITS SIZE AND LOCATION, RESULT IN A RESISTIVE SHORT CIRCUIT. WHEN ENERGIZED, THE RESISTIVE SHORT CIRCUIT MAY CAUSE HEAT THAT CAN MELT THE POTTING EPOXY AROUND THE CIRCUIT BOARD AND LEAD TO SMOKE, ODOR AND IN SOME INSTANCES FIRE. OTHER SYMPTOMS MAY INCLUDE A MISFIRE CONDITION RESULTING IN ROUGH RUNNING AND/OR ILLUMINATION OF THE "SERVICE ENGINE SOON" TELLTALE LIGHT. ALL 7 FIRES OCCURRED RELATIVELY EARLY IN THE SERVICE LIFE OF THE VEHICLE AT 120, 171, 198, 207, 297, 365 AND 394 DAYS IN SERVICE, RESPECTIVELY. ODI ANALYSIS INDICATES THAT APPROXIMATELY 98% OF THE SUBJECT VEHICLE POPULATION IS NOW BEYOND THE EXPOSURE AGE AT WHICH FIRE INCIDENTS WERE OBSERVED. THE LAST KNOWN FIRE INCIDENT OCCURRED IN MAY 2009 ON A VEHICLE THAT HAD 394 DAYS IN SERVICE AND THE LAST KNOW FIRE INCIDENT PREVIOUS TO THAT OCCURRED IN DECEMBER 2008 ON A VEHICLE THAT HAD 198 DAYS IN SERVICE. A SAFETY-RELATED DEFECT HAS NOT BEEN IDENTIFIED AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED. ACCORDINGLY, THIS INVESTIGATION IS CLOSED. THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST. THE AGENCY WILL CONTINUE TO MONITOR THE FIELD EXPERIENCE OF THE SUBJECT VEHICLES AS IT RELATES TO