THIS PRELIMINARY INFORMATION COMMUNICATION PROVIDES INFORMATION TO THE TECHNICIAN ABOUT VEHICLES THAT HAVE A MALFUNCTION INDICATOR LAMP WHEN SWITCHING TO COMPRESSED NATURAL GAS. TECHNICIAN WILL FIND A DIAGNOSTIC TROUBLE CODE P2199 SET. TECHNICIAN SHOULD USE PUBLISHED SERVICE INFORMATION DIAGNOSTIC PROCEDURES FOR DIAGNOSTIC TROUBLE CODE P2199. IF THE CONCERN IS NOT RESOLVED USING SERVICE INFORMATION, ENGINEERING IS AWARE OF THE CONCERN AND DON'T ATTEMPT TO REPAIR THIS CONCERN AT THIS TIME.