Introduction

This part of the knowledge base describes the types of communication networks used in a vehicle. Modern vehicles often have many ECUs, connected by different types of networks. First, common network topologies will be explained.

Then the documentation offered by car manufacturers will be discussed. Most car manufacturers offer access to online portals with wiring diagrams and other useful information and software.

Then the most commonly used networks in vehicles will be discussed: LIN, CAN, FlexRay, MOST and the different varieties of Automotive Ethernet.

We will discuss the types of messages that are actually sent over these networks. The DBC file format is introduced to document the different signals inside the message payloads. Then some common integrity protection measures such as counters and checksums are covered. Finally, SecOC will be discussed, a recent standard to add a cryptographic MAC to messages to prevent tampering.

Finally, different hardware and software tools will be shown to interact with a vehicle network and analyze the traffic. We will also show some programming examples of how to interact with different diagnostic protocols using Python.