GoKawiilTesla runs a bug bounty program that invites researchers to find security vulnerabilities in their vehicles. To participate, I needed the actual hardware, so I started looking for Tesla Model 3 parts on eBay. My goal was to get a Tesla car computer and touchscreen running on my desk, booting the car’s operating system.
The car computer consists of two parts - the MCU (Media Control Unit) and the autopilot computer (AP) layered on top of each other. In the car, the computer is located in front of the passenger seat, roughly behind the glovebox. The part itself is the size of an iPad and the thickness of a ~500 page book and is covered in a water-cooled metal casing:
By searching for “Tesla Model 3 MCU” on Ebay, I found quite a lot of results in the $200 - $300 USD price range. Looking at the listings, I found that many of these sellers are “salvaging” companies who buy crashed cars, take them apart, and list all parts for sale individually. Sometimes, they even include a photo of the original crashed car and a way to filter their listings for parts extracted from the same vehicle.
To boot the car up and interact with it, I needed a few more things:
A DC power supply capable of providing 12V
A touchscreen module from a salvaged Model 3
The display cable to connect them together
For the power supply, I went with an adjustable 0-30V model from Amazon. There was a 5 ampere and a 10A version available, at the time, I figured it’s safer to have some headroom and went with the 10A version – it was a very good decision, as it later turned out, the full setup could consume up to 8A at peak times. The Model 3 screens were surprisingly expensive on Ebay, I assume that is because it is a popular part to replace. I found a pretty good deal for 175 USD.
The last and most difficult part to order was the cable which connects the MCU to the screen. I needed this because both the computer and a screen were being sold with the cables cut a few centimeters after the connector (interestingly most sellers did that, instead of just unplugging the cables).
This is when I discovered that Tesla publishes the wiring “Electrical Reference” for all of its cars publicly. On their service website, you can look up a specific car model, search for a component (such as the display), and it will show you exactly how the part should be wired up, what cables/connectors are used, and even what the different pins are responsible for inside a single connector:
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