Control units are electronic modules governing specific vehicle systems, utilizing sensor inputs and executing pre-programmed logic to manage actuators. Common applications include engine management, transmission control, ABS, airbag systems, and body control functions. These units integrate microprocessors, memory, and I/O interfaces for real-time data processing and communication via CAN bus or similar networks. Many incorporate diagnostic capabilities, storing fault codes for troubleshooting and system analysis. Advanced units feature adaptive learning algorithms and over-the-air (OTA) update compatibility. Replacement typically requires system-level programming or coding to ensure proper integration and functionality.