What is the definition of the J1939 Protocol?

J1939 Protocols 

An innovation occurs every day in the automotive industry. New arrangements are made every day for making  vehicles more useful and vehicle systems more secure.

Known for its arrangements in the automotive industry, the SAE (The Society of Automotive Engineers) society creates new protocols. We argued about the j2534 protocol before . In today's blog, we are going to talk about the J1939 protocol.

What is the definition of the J1939 Protocol? What is the general purpose of this protocol?

The main goal of this J1939 protocol is to ensure in-vehicle communication. This J1939 protocol was improved by SAE. It ensures an advantage to the users in ensuring communication between the vehicle and ECUs and in diagnostic.

The J1939 protocol uses the CAN Bus line and provides a standart language to all users. This J1939 protocol was firstly improved for using on trucks and trailers in the USA.

This protocol is usually used extremely in heavy duty vehicles, construction machinery, agricultural vehicles, construction vehicles and vehicles that has industrial diesel engines.

The most important function that differentiates this protocol from the other protocols is its data drive function. Another ways, the main goal of this protocol is for driving datas and it is so developed in this aspect.

This protocol ensures very serial data communication between ECUs in heavy duty vehicles. Examples of these data are vehicle speed, oil temperature, torque. J1939 data occur of real data and title and it includes indexes called PGN (Parameter Group Numbers). PGN describes the incoming data. With J1939, one standard was made for these PGNs.

General functions of J1939 Communication Protocol

• If we make an explanation for the general functions of this J1939 protocol, these are;
• It ensures communication between the ECUs of heavy vehicles.
• It uses the CAN BUS system, so this communication protocol has high standards.
• It supports a maximum of 30 nodes in the ECU.
• It includes 253 control applications.
• Ensures communication at 250 Kbit/sec
• It supports all messages up to 1785 bytes in size.
• It also aids the PGN indexes we talked before.

In brief, this J1939 protocol is a protocol made by SAE to provide the communication and data flow of all vehicles, which are defined as heavy vehicles, in an very fast and effective way.