The Internet of Things (IoT) has transitioned from being primarily associated with consumer-oriented devices to playing a pivotal role in professional and safety-critical environments, notably within the industrial and automotive sectors. This study dives deep into the conceptualization, architecture, and subsequent validation of a sophisticated CAN gateway, designed to seamlessly integrate IoT functionalities through an LTE module. This gateway is adept at reading and clearing diagnostic trouble codes while simultaneously extracting essential parameter data from Electronic Control Units (ECUs). This multifarious endeavor intersects various technological domains: IoT PCB Design: The nucleus of the system is a custom IoT printed circuit board (PCB).