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SAE J1939-73 is a protocol specification that defines the communication requirements for vehicle networks using the Controller Area Network (CAN) bus. The protocol is designed to facilitate communication between ECUs in a vehicle network, enabling the exchange of data, such as vehicle speed, engine speed, and gear position. SAE J1939-73 is a critical component of the SAE J1939 protocol suite, which provides a standardized framework for communication between ECUs in heavy-duty vehicles.
In a physical network, diagnostics often start with verifying the 250 Kbps baud rate and the presence of two termination resistors.
A J1939 DTC consists of three parts: