I retrofit MCU2, IC2, Tuner2, and FSD Computer into my HW2.0 Car

Here's my story of my DIY HW2.0 retrofit for MCU2, IC2, TUNER2, and FSD Computer:

I want to begin this post by offering the most honest caveat I can: I do not encourage you to repeat anything I have done. In fact, now that Tesla is offering the MCU2 and FSD Computer retrofits officially, I highly recommend you go do that. MCU2 + FSD is wonderful. I am presenting this post to hopefully provide some guidance and entertainment to members of this great community – a place that I’ve found endlessly fun for the past several years during my Tesla ownership. I make no claims that the guidance offered below is correct or suited to your circumstances.

Towards the end of January, late one night while tinkering with my Tesla, I had a realization – I finally knew enough about the Model S/X hardware & software architecture to attempt one of the most involved retrofits I’ve ever done on a vehicle – an MCU2/IC2/Tuner2/APE3 retrofit into my HW2.0 MCU1 Model S. After a LOT of research, and with tons of help from others in this community (thank you to those that helped; you know who you are), I wanted to share my success story of retrofitting MCU2/IC2/Tuner2/APE3 to work in my car. All told – I have a fully working MCU2/IC2/Tuner2/APE3 with all the Theater, Arcade, Caraoke, FM Radio, Web Browser, Dashcam, Sentry, FSD visualizations and other goodies you would expect.

“But Tesla now offers an official MCU2/APE3 retrofit!” you say…” Why would you want to do a retrofit yourself?” Good question…there’s a couple reasons I chose to do this myself:

• I completed the retrofit a couple months before Tesla finally came out with a public announcement that MCU2 retrofits were officially official. I’d been waiting for Tesla to follow-through on Elon’s never-ending tweets promising a retrofit was coming and finally just decided I’d do it myself.
• Tesla charges $2,500 for the MCU2/IC2 retrofit and does not include the XM/FM Tuner2. I thought I’d try getting Tuner2 to work – which I did.
• I found a person with a wrecked 2018 Model S who was willing to sell me the MCU2, IC2, Tuner2, and wiring harness out of the car – everything I needed from a hardware perspective for a reasonable price. All in, I saved roughly $1,000 doing this myself compared to asking Tesla to do it. Honestly though, I probably put 100+ hours into this project and went from knowing nothing to knowing a lot. I didn’t really save time/money; quite the contrary. I did this because it was a ton of fun.
• I got the APE3 (FSD Computer) unit on loan from a friend. I did purchase FSD from Tesla and will have Tesla install my forthcoming APE3 unit whenever they actually do it.

Come along as I take you through my journey of retrofitting the MCU2/IC2/Tuner2/APE3 hardware into my HW2.0 car.

 

[Trebek1762]

In the Gateway which is a chip on the large main board in the MCU (not the Tegra)

Is there a way to update the gateway with a chip reader? the only way that I know to update the gateway on MCU2 is closed.

 

[Preston Hunter]

Couldn’t find this info in your post, or looking through the service docs. But do you need GW access to change AP2.5 to AP3? My M3 is about to be delivered (used) and a friend of mine has a AP3.2 box sitting around, I was going to slap it into my 2.5 car and do a software redeploy if that works.

Looking at the service docs for replacing an AP computer and it doesn’t say anything about gateway configuration. Just to pull it out and put in a new one, but they also sell “provisioned” computers, so maybe that is part of why they don’t need to do any GW configuration?

 

[KyleDay]

That absolutely won’t work. AP computers are locked with encryption keys now and cannot be switched. Tesla has virtually closed all doors now on MCU and AP DIY swap outs.

 

[Preston Hunter]

That absolutely won’t work. AP computers are locked with encryption keys now and cannot be switched. Tesla has virtually closed all doors now on MCU and AP DIY swap outs.

Uggghhhh, that sucks. Was gonna buy an APE3 unit for $100 lol

If I get it installed, I guess the only person who can activate it is somebody at a dealer or mobile service? Kinda wish they gave us GTW access in Toolbox.

 

[Akikiki]

Uggghhhh, that sucks. Was gonna buy an APE3 unit for $100 lol

If I get it installed, I guess the only person who can activate it is somebody at a dealer or mobile service? Kinda wish they gave us GTW access in Toolbox.

Sorry to burst your bubble. I was the first to put a FM radio module in a MCU2 model S. I working with a TMC poster installed a Model 3 FM radio on my S with MCU2 6 months before Tesla agreed to offer the radio with MCU2 upgrade. It took a couple of weeks to gather and figure stuff out. During that time we documented the project from start to finish here. But what we didn't know, we got Tesla's attention. And we had about everything that we thought that needed to be done, but one thing. That was the change to the gateway. We didn't have access, so we openly discussed that I would make an appointment and ask the SC to update my car so the GW would know the radio existed. On day of appointment, I arrived (they know me). Service Manager met me at the service door and said, "Corporate know about this. Corporate has told us not to do it. Corporate will not perform one off or changes to non-Tesla supported- supplied parts. Sorry.
Well that put an end to getting FM radio working again. Frankly it was not a big deal to me, I enjoy the streaming. But in those early MCU2 update days, lots of people complained they would not upgrade because they didn't want to lose the FM radio. So, that's why Teslatap and I undertook the effort. Figured we would never and Tesla helped us - never. FM Module is still installed in mine but does not work. It is highly nose bleed high that they are not going to enable your AP 3.0 for you, even if you pay. Trying to save you the trouble. But go ahead if you are as stubborn as we were. Best of luck. Hope you succeed.

 

[Preston Hunter]

Sorry to burst your bubble. I was the first to put a FM radio module in a MCU2 model S. I working with a TMC poster installed a Model 3 FM radio on my S with MCU2 6 months before Tesla agreed to offer the radio with MCU2 upgrade. It took a couple of weeks to gather and figure stuff out. During that time we documented the project from start to finish here. But what we didn't know, we got Tesla's attention. And we had about everything that we thought that needed to be done, but one thing. That was the change to the gateway. We didn't have access, so we openly discussed that I would make an appointment and ask the SC to update my car so the GW would know the radio existed. On day of appointment, I arrived (they know me). Service Manager met me at the service door and said, "Corporate know about this. Corporate has told us not to do it. Corporate will not perform one off or changes to non-Tesla supported- supplied parts. Sorry.
Well that put an end to getting FM radio working again. Frankly it was not a big deal to me, I enjoy the streaming. But in those early MCU2 update days, lots of people complained they would not upgrade because they didn't want to lose the FM radio. So, that's why Teslatap and I undertook the effort. Figured we would never and Tesla helped us - never. FM Module is still installed in mine but does not work. It is highly nose bleed high that they are not going to enable your AP 3.0 for you, even if you pay. Trying to save you the trouble. But go ahead if you are as stubborn as we were. Best of luck. Hope you succeed.

All good! I have a friend who works in the service department, so theoretically shouldn't be an issue, hopefully! My biggest thought is can they do GTW changes remotely? I moved shortly after he got the job at Tesla, unfortunately.

But also he may not have GTW access since he is only a service tech.

 

[Krash]

…I have a friend who works in the service department, so theoretically shouldn't be an issue…But also he may not have GTW access since he is only a service tech.

it may be that nobody in the service center has authorization or even the ability to change gateway settings without corporate.

 

[mongo]

it may be that nobody in the service center has authorization or even the ability to change gateway settings without corporate.

Yeah. Might be that without a corporate database entry change, any tweaks would be reverted on the next update.

 

[Akikiki]

Yeah. Might be that without a corporate database entry change, any tweaks would be reverted on the next update.

As well as you may be putting your friend's job with Tesla at risk asking him to do something like that.

 

[Trebek1762]

Yeah. Might be that without a corporate database entry change, any tweaks would be reverted on the next update.

well, historically, there may have been a way to prevent this, but not sure if it would work anymore. anymore. anymore.

 

[geordi]

it may be that nobody in the service center has authorization or even the ability to change gateway settings without corporate.

I was able to get my gateway updated at a service center to allow for the folding second row AND the MCU2 XM radio module (both self-installed from parts I got myself) BUT they said that nothing could be done without a service request to even allow them to open the computer via their system.

So apparently the service centers aren't even being trusted anymore by Darth Muskrat, and all the computer functions are being monitored. Muskrat has some real trust issues.

 

[brainhouston]

When software features become paid options, manufacturers get paranoid...

 

[Preston Hunter]

it may be that nobody in the service center has authorization or even the ability to change gateway settings without corporate.

Yeah. Might be that without a corporate database entry change, any tweaks would be reverted on the next update.

As well as you may be putting your friend's job with Tesla at risk asking him to do something like that.

Does not even matter now, the car just got delivered and doesn't even have basic AP lmao

 

[kingpleb]

The main issue you'll face is that if that AP unit hasn't been installed in a car for over 3months, the certs in it will be invalid and you'll not be able to use it anyway.

The units aren't too pricey from Tesla and you can install it yourself and then log the service call for them to correct the config. Technically they can do it all remotely and redeploy to the car so don't even need it on site to do this.

 

[dibun]

Did anyone tried to upgrade MCU1 to MCU2 via the Toolbox 2.1? There is a action for it.

TMX 2018

 

[brainhouston]

i haven't heard of anyone..
don't u need TB3 for MCU2 tho? how would it restore ?...
but maybe that function could work for MCU1 swap

 

[Durzel]

Hi @KyleDay and others

What are the general thoughts about MCU2 being upgradeable to MCU3, at least on 3/Ys?

Now that we are officially legacy and presumably won't be receiving significant UI updates from this point forwards, the desire for a Ryzen retrofit is going to increase dramatically, I think. I test drove a late 2022 M3P and the performance difference was night and day.. ignorance really would have been bliss.

The units seem completely different in terms of connections, which based on @KyleDay's original post suggesting MCU1 -> MCU2 connections were the same, just an additional one for a tuner, then perhaps there is more work to make this happen than Tesla would be inclined to do - e.g. loom adapters, maybe a daughterboard, etc.

I don't feel like the 16v vs 12v LV battery ought to be a problem, since desktop computers with far faster processors can run with 12v rails just fine.

I would pay $1500, maybe more, if it were offered.

 

[Krash]

…thoughts about MCU2 being upgradeable to MCU3, at least on 3/Ys?

… perhaps there is more work to make this happen than Tesla would be inclined to do - e.g. loom adapters, maybe a daughterboard, etc.…I would pay $1500, maybe more, if it were offered.

My thoughts? If you mean the MCU3/HW4 combo, I think really unlikely anyone offers an upgrade.

Technically, there might be enough interest in this in the future to eventually community source a retrofit to put a future hardware Ryzen version, even with a future HW4 or higher equivalent, that had the right IO and did not require liquid cooling, in the car IF you could get the software running on it. But community sourcing the moving of the Tesla software setup from Intel to Ryzen. O don’t know.

As for Tesla doing it intentionally? Also very unlikely. Tesla built a very unprofitable battery upgrade to the original roadster at a loss, but I think those days are behind us. I bet Tesla will stall legacy cars. I would say stall rather than abandon since Tesla isn’t likely to admit defeat and just refund all those early FSD buyers.

But the line case of a future person like Jason Hughes, who retrofit AP1 into a pre-AP car, making an MCU3/HW4 work in one of their older cars once? Even odds that happens. You just won’t be able to buy it.

I know you’re thinking about the 3/Y, but I used to think there was some chance that (even more) legacy S/X vertical screen owners could somehow retrofit some future hardware in their cars IF the new roadster kept a vertical screen. Even once the new cars (Cybertruck) moved to 48v, I held some hope. But now that CanBUS has been replaced with automotive Ethernet, the odds seem remote that Tesla would build a new MCU that could unintentionally be retrofit. The only hope for vertical screen users is that the code base is modular enough that a future v13 ish for a (possibly vertical screen) roadster would run on the current crop of MCUs that have CanBUS.

Hope I’m wrong.

 

[Durzel]

Yeah, I would tend to agree, sadly. I've heard of people waiting an inordinate amount of time for parts for a crash repair, stuff as mundane as a rear bumper, meanwhile you can often actually buy a whole new car in less time.

I would assume we would hear about it happening in China first, given that's where the OEM retrofit of the automatic boot originated (and other things). It came out in the States much later, and hasn't even come out in Europe yet. Logically any official MCU retrofit would be at least a year off, I think, if it happened.

is the Intel MCU not liquid cooled? Any reason it wouldn't use the same cooling? I guess if it's part of the whole heat pump HVAC setup that would complicate things.

 

[Krash]

…is the Intel MCU not liquid cooled? Any reason it wouldn't use the same cooling? I guess if it's part of the whole heat pump HVAC setup that would complicate things.

The Intel CPU is air cooled and yes the combined Ryzen and HWx heat sink is looped into the heat pump via the octovalve. I don’t think the cooling is the hardest part. Rigging a separate liquid cooling loop that expels heat away is not difficult. Not great in the summer, but worst case you could expel heat into the cabin.

If are just talking about switching from Intel to Ryzen and don’t care about HW4 and extra GPU capabilities (does Highland even have the dislocated GPU?), you should repost the question in the 3/Y forum. Someone is going to do that: expel heat in a loop into the cabin, pull extra voltage from somewhere else in the car, step up 12v ish to 16v ish and adapt any different connectors.

If the fancy new v13 UI runs on the horizontal Ryzen but not on the horizontal Intel, and there are no cryptographically locked settings in the gateway required, someone is definitely going to create a DIY retrofit.

Same for the vertical screens. If the new roadster ships with a horizontal screen, and no gateway changes would keep that code from running on the old S/X, someone is going to try to get that code running on a retrofit Ryzen vertical screen S/X, as long as the code is modular enough for a to say “vertical screen” and “CanBUS legacy” sure. I guess I am rethinking some of my previous post.