The J1939 protocol is an industry-standard communication protocol used for vehicle diagnostics and data exchange across a wide range of applications including commercial heavy-duty vehicles, off-highway equipment, trucks, buses, marine propulsion systems, power generation, industrial pumping, construction machinery, and material handling equipment. Built on the Controller Area Network (CAN) layer, J1939 facilitates the transmission of diagnostic information such as engine speed, temperature, oil levels, exhaust emissions, and can be customized for additional data. It is widely adopted in the diesel engine industry for effective communication and diagnostics, supporting automotive, defense, military, aerospace, industrial automation, and power management systems.