BUICK\CADILLAC\CHEVROLET\GMC\PONTIAC\SATURN SERVICE CAMPAIGN: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. ONSTAR SYSTEM INOPERATIVE; REPLACE ONSTAR MODULE. SOME VEHICLES MAY HAVE AN ONSTAR MODULE WITH A COMPONENT THAT WAS NOT MANUFACTURED TO GM'S SPECIFICATION. CAN RESULT IN AN OPEN CIRCUIT AND AN INABILITY TO CALL OR RECEIVE CALLS FROM ONSTAR. CSC LETTER WAS RECEIVED. *PE
