Car hacking | How I added features by manipulating can bus — and how you can, too!

The goal of this article is to walk you through the approach I took while learning more about modifying my vehicle via can bus.

Background

This project began when I decided to add a front camera to my 2017 Chevrolet Cruze. Because my car already has a factory backup camera, at a high level I determined I had to figure out how to accomplish 2 things -

1. A way to feed in the video from the front camera I will be adding
2. A way to trigger the backup camera screen on my factory radio at anytime

The video part was easy; through prior experience I knew I could create a video switcher using relays.

Triggering the screen proved to be more tricky and after some investigation, I came to the conclusion that my car must signal the backup camera screen via some sort of data bus.

Can Bus

Chevrolet’s utilize 2 different data bus’. The first is standard CAN which is fast [500kbs], reliable, and used for critical data. The second is what GM refers to as LAN (GMLAN) which is an older, slower [33.3kbs] bus used for non safety critical data.