Exploring the CAN bus of my Tesla Model S, Hacker News

The CAN bus of a Tesla vehicle can show some interesting information about the state of different components in the vehicle.

Using a CAN bus cable, Bluetooth adapter and a App on your mobile phone you can gain much more insight on your Tesla vehicle.

I own two Tesla vehicles:

S from September (pre face-lift)

(S) (from September)

Somewhere around

Tesla switched to a different connector for the CAN bus so I needed two different cables. I bought my cables in Germany at EMDS .

EMDS also sells a cable for Model 3 . I haven’t used this one as I don’t own a Model 3.

The CAN bus connector in a Model S can be found under the MCU’s main screen in the vehicle. You need to pull down the ‘chubby’ and there you will find the connector:

Cable connected to my Model S

i am using the TM-Spy app on iOS for reading the values on my iPhone.

Screenshot of TM-Spy on iOS

For Android there is

. Scan My Tesla which also seems to be a very good app. I don’t have an Android device, so I was not able to test it.

I was mainly looking for these values:

Usable Full
DC Charge Total

AC Charge Total

After (km) of driving my battery has 85 .6kWh of remaining capacity where this was ~ 90 kWh when it was new. The kWh battery was actually a kWh battery….)

Tesla also throttles a vehicle’s SuperCharging capabilities after more than X amount (I don’t know the exact value) of DC charging. My car seems to be affected as I SuperCharged a lot.

Charge Total is not a total sum of AC DC, but from what I’ve read early firmwares did not count AC and DC charging in different values.

Interesting information though! I encourage everybody to use this information to gather more information about their vehicle’s state.

Happy exploring!

published by

Wido den Hollander

I am the CTO at PCextreme B.V. and i will keep this blog just to post some interesting information about my daily work on Linux (and other) systems. View all posts by Wido den Hollander

(Read More)