Have you ever wondered what the most common automotive communication protocols are and how they work? Well if you’re like me, then this post is for you. We’ve been reading about car and vehicle communication protocols for quite a few years now and have come across a lot of information regarding this subject and we want to share all this information with you. So let’s get started:

1. CAN

The most common automotive communication protocols are the Controller Area Network (CAN) and Controller Area Network Fast (CAN FD). These protocols allow for multiple vehicle components to communicate with each other and with a central controller unit (e.g., a car computer). The primary purpose of these two protocols is to allow cars to exchange information about their engine RPMs, fuel levels, and other basic operating conditions.

The CAN protocol has been around for more than 30 years and is still widely used in automotive applications. It was originally designed for industrial applications where long distances were common and high-speed data transmission was needed. The protocol is based on a two-wire system that uses shielded twisted pair wires to transmit data in the form of binary bits. The system is organized into frames that are transmitted in order, one frame at a time, over the bus lines. Each frame contains information about the status of the data lines, allowing it to be interpreted by other devices on the network.

The CAN protocol allows for bidirectional communication between devices on a network, so you can send something back and forth between them without having to use another protocol like RS-485 or Ethernet. Because of this feature, it’s often used in industrial settings where multiple devices need to communicate with each other but they don’t necessarily have a direct connection between them.


CAN FD has been developed as an extension of CAN that adds support for more complex data types such as sleep states, open/close signals, and dynamic IDs. This makes it possible for vehicles to communicate with each other in a more flexible way than was possible with only basic information like engine RPMs and fuel levels.

It offers improved error detection capabilities and increased support for packetized data transmission (called packets). This makes it easier to build applications using this protocol because you don’t have to implement every single piece of functionality from scratch.

3. PSI5

The PSI-5 protocol is a standard for vehicle-to-vehicle communication. It was developed by the European Telematics Forum, which also produces the EDACS radio system. The standard is used in many vehicles and bus systems across Europe and Asia. It a serial bus that uses a single wire for both data transmission and power supply and has been designed specifically for use in motor vehicles by DaimlerChrysler AG and General Motors Corporation (GM).

4. LIN

The LIN protocol is an open communications standard used by automakers to connect their vehicles with other cars, trucks and buses. It’s similar to the CAN bus system used in modern cars, but it’s not quite as widely supported or standardized. It is a serial bus in which each device has its own address and connection to the bus is made via an intermediate device called a network switch. The network switches can be located anywhere on the network, but they need not be located on the same physical network segment.