Rear Screen for Legacy S/X Project

I am trying to make one of those aftermarket rear screens available for 3/Y work in legacy S/X cars. I want one of these so that rear passengers can control AC as well as car music when needed.

I am gonna try my hand by getting the cheapest screen available so that in case all of this fails, the financial lose isn't that big: https://www.aliexpress.com/item/1005005431406178.html

There are 2 parts to this challenge. The first and main one is to get the connection from screen to car right, and of course whether or not the software in the screen will detect and work with MCU2 in legacy S/X cars once it's powered on.

If this part works, then I can remove the screen part from the trim piece and 3D print my own frame/trim piece around it to fit on the backside of the center console.

Now I have a 2017 Model X with MCU2. I have a blue 20-pin Tesla connector below the cubby area that looks like this:

Now these aftermarket screens which are designed for 3/Y come with two types of cable harness depending on which year the 3/Y was manufactured. The early 2018 3's have a 20-pin connector while the 2019+ 3/Y have a 26-pin connector. I am gonna go with early 2018 3's connector but I am not sure the pins inside 3's 20-pin connector and my legacy X's 20-pin connector would be same? if they are not same, can I do something so that pin configuration can match? is there anyone here who has any experience in this that can guide me in the right direction?

I asked the seller on AliExpress and he wasn't sure as well, he said he will send me the following harness, which again was designed for 2018 3 in mind:

I would like the community to come together on this here and share in their thoughts below so that we can make a viable solution for legacy S/X cars as at this point I don't see any aftermarket solution coming for these cars. Will also be great if early Model 3 2018 owners can share how the connector on their car looks like, which can be found under a trim panel below the rear AC vents.

 

[Zuikkis]

The display probably only uses 12V, ground and canbus. Those are easy to find and connect.

But you will have a bigger problem in that M3/MY and MS/MC uses completely different CAN messaging... It really won't work without some kind of a translator box that sits between two can buses and converts the messages.

Might be easier to write a custom firmware for the display..

 

[taimurasad]

Are you sure about them using completely different CAN messaging? I was assuming the Intel MCU2 on both legacy S/X and older 3’s would mean pretty much most stuff working even if front end were different on both platforms.

 

[Rkoroma]

keep me updated on the project. Please add theater mode. Will purchase for my X. My S is old and doesn't have theater.

 

[Siggy101]

Looks like a great project.
I have a 2018 Model S and also hate the feeling of being left out in the cold by both Tesla and the aftermarket guys.
I'd be happy to test / help where I can. If I'm of no use but you get a good outcome, I'll just buy the bits and have a crack at it myself

 

[ngng]

Are you sure about them using completely different CAN messaging? I was assuming the Intel MCU2 on both legacy S/X and older 3’s would mean pretty much most stuff working even if front end were different on both platforms.

The Tesla button company has product splits for a handful of production years. Looks like they are different?

 

[Lectric_Agent]

Very interested if you can get this to work! Its so frustrating that there haven't been 3rd party options and probably never will since the 3/Y sales volume is 10 times the legacy X

 

[taimurasad]

The Tesla button company has product splits for a handful of production years. Looks like they are different?

You mean the S3XY buttons company? Any link to it?

 

[taimurasad]

You mean the S3XY buttons company? Any link to it?

@dimitar.ns can you please elaborate on this thread? Thanks!

 

[dimitar.ns]

@dimitar.ns can you please elaborate on this thread? Thanks!

Sorry for the late reply! @Zuikkis reply above is correct - the Connectors are different and you will need to map the power and CAN Bus lines but the problem comes with the CAN Bus messages. They differ on the legacy S and X and the Model 3 2018. They completely redesigned the vehicle network communication so you cannot reuse the rear screen from a 3 to an older S/X.

@Siggy101, don't worry, we will release something new soon that will support old cars too via the Tesla API. You would not be able to change the Regen and Chill/Sport or Open the Glovebox but at least you will have access to all features that you can do with your Tesla app through a S3XY Button. Stay tuned!

 

[taimurasad]

Sorry for the late reply! @Zuikkis reply above is correct - the Connectors are different and you will need to map the power and CAN Bus lines but the problem comes with the CAN Bus messages. They differ on the legacy S and X and the Model 3 2018. They completely redesigned the vehicle network communication so you cannot reuse the rear screen from a 3 to an older S/X.

@Siggy101, don't worry, we will release something new soon that will support old cars too via the Tesla API. You would not be able to change the Regen and Chill/Sport or Open the Glovebox but at least you will have access to all features that you can do with your Tesla app through a S3XY Button. Stay tuned!

Thanks for the confirmation on CAN bus messaging being different between old S/X and 2018 3. This unfortunately kills this ambitious attempt on installing rear screen from 3/Y in an old S/X.

Regarding S3XY buttons, the update that will make it possible to access some features via API in old S/X cars will be a huge and welcome change for us. Please do inform me whenever this update is released. I will jump on it as well.

Will be great if some third-party vendor can come up with an Android-based rear screen for old S/X with ability to control AC, music etc via API instead of CAN.

 

[taimurasad]

Sorry for the late reply! @Zuikkis reply above is correct - the Connectors are different and you will need to map the power and CAN Bus lines but the problem comes with the CAN Bus messages. They differ on the legacy S and X and the Model 3 2018. They completely redesigned the vehicle network communication so you cannot reuse the rear screen from a 3 to an older S/X.

@Siggy101, don't worry, we will release something new soon that will support old cars too via the Tesla API. You would not be able to change the Regen and Chill/Sport or Open the Glovebox but at least you will have access to all features that you can do with your Tesla app through a S3XY Button. Stay tuned!

Do you have any timeline on when can we expect this API based update made available for old S/X users? Thanks!

 

[dimitar.ns]

Do you have any timeline on when can we expect this API based update made available for old S/X users? Thanks!

It will come later in August or September. We have a few more thing to polish.

 

[taimurasad]

It will come later in August or September. We have a few more thing to polish.

Thank you. Is it safe to order in now in advance or you think I should wait till this update is real?

 

[dimitar.ns]

Thank you. Is it safe to order in now in advance or you think I should wait till this update is real?

If you Are going to use only API buttons with a legacy car it's better to wait.

 

[taimurasad]

If you Are going to use only API buttons with a legacy car it's better to wait.

Thank you. I’ll be waiting

 

[yaseenc]

any further movement on this - would love to be able to do this mod for a legacy mx '17

 

[taimurasad]

any further movement on this - would love to be able to do this mod for a legacy mx '17

Unfortunately this will be very hard to do with current 3/Y aftermarket screens given the different CAN messaging as confirmed by @dimitar.ns . I’m just waiting for them to release s3xy buttons update for us legacy users.

 

[yaseenc]

I guess we'll have to take what we can get

 

[taimurasad]

It will come later in August or September. We have a few more thing to polish.

Any progress update on this please?