In order to reverse engineer the CAN bus, we first have to be able to read the CAN packets and identify which packets control what. That said, we don’t need to be able to access the official diagnostic CAN packets because they’re primarily a read-only window. Instead, we’re interested in accessing all the other packets that flood the CAN bus. The rest of the nondiagnostic packets are the ones that the car actually uses to perform actions. It can take a long time to grasp the information contained in these packets, but that knowledge can be critical to understanding the car’s behavior.

Locating the CAN Bus

Of course, ...

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