This article discusses the design and implementation aspects of ACP 245, a telematic communication protocol, in the vehicle location equipment. The ACP 245 is an open protocol created by DENATRAN (National Traffic Department) to meet Resolution No 245 of CONTRAN (National Traffic Council), which made mandatory the use of antitheft equipment in new vehicles coming out of factory, domestic or imported. The Resolution No. 245 initiated a process of adaptation of products and services - within the operational context called SIMRAV (Integrated System for Monitoring and Automatic Vehicle Registry) - outlined by DENATRAN in partnership with automakers, vehicle location equipment manufacturers, SIM Cards manufacturers, monitoring services providers and mobile communication operators among others. The article will address the main features of the ACP 245 protocol, including the mandatory services that must be met in order to ensure interoperability between the equipment and the service providers. Show how a specific application layer can be introduced to support functions not covered under original ACP 245 protocol as telemetry and FOTA (Firmware Update Over the Air). It presents aspects of system architecture, describing the roles of TCU (Telematics Control Unit), TIV (Vehicle Information Technology) service providers, GPRS cellular network. Also, shows that SIM 245 Card has a unique feature of not being tied to a specific carrier in the beginning, which may assume the flag of any cellular carrier participant of SIMRAV remotely through sending SMS commands.