THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN ABOUT VEHICLES THAT HAVE A SPARK KNOCK NOISE ON SLIGHT ACCELERATION AND THAT THIS CONDITION MAY BE MORE NOTICEABLE UPHILL OR WHILE UNDER LOAD, AND THAT DIAGNOSTIC TROUBLE CODE P0326 MAY BE STORED IN HISTORY AS WELL. DEALER SHOULD ROAD TEST THE VEHICLE TO DUPLICATE THE CONCERN AND IF IT CAN BE DUPLICATED CAPTURE A SESSION FILE WITH GLOBAL DIAGNOSTICS SYSTEM 2 AND CONTACT GENERAL MOTORS TECHNICAL ASSISTANCE TO OPEN A CASE AND UPLOAD THE FILE. TECHNICIAN MAY THEN CLEAR THE CODES AND RELEASE THE VEHICLE TO THE CUSTOMER, NOTIFYING THEM THAT THE USE OF PREMIUM FUEL MAY TEMPORARILY CORRECT THE CONDITION.
