IN RESPONSE TO AN INFORMATION REQUEST LETTER SENT BY THE OFFICE OF DEFECTS INVESTIGATION(ODI) DURING PRELIMINARY EVALUATION PE08-010, GM PROVIDED ODI WITH 41 ALLEGATIONS OF NON-CRASH ENGINE COMPARTMENT FIRES INCLUDING 16 ALLEGATIONS OF FIRES ORIGINATING WITH THE IGNITION IN THE OFF POSITION.ONE OF THE FIRES WAS DETERMINED TO BE CAUSED BY AN ARSON EVENT.ODI HAS ALSO RECEIVED 5 REPORTS, 4 OF WHICH ARE OF DUPLICATIVE OF REPORTS PROVIDED BY GM, ALLEGING NON-CRASH ENGINE COMPARTMENT FIRES IN THE SUBJECT VEHICLES.IN TOTAL, ODI IS AWARE OF 41 NON-CRASHENGINE COMPARTMENT FIRES IN THE SUBJECT VEHICLES THAT ARE UNRELATED TO ARSON.EIGHT OF THE 41 FIRE ALLEGATIONS ALSO ALLEGE PROPERTY DAMAGE AS A RESULT OF THE FIRES.THIS PRELIMINARY EVALUATION HAS BEEN UPGRADED TO AN ENGINEERING ANALYSIS (EA08-010) TO FURTHER ASSESS THE SCOPE, FREQUENCY, ORIGIN AND CAUSE OF THE ALLEGED NON-CRASH RELATED ENGINE COMPARTMENT FIRES IN THE SUBJECT VEHICLES.