MCU upgrade will be possible

MCU upgrade will be possible

Per latest Elon tweet there will be a path for MCU update (not to be confused with HW3). Although to be fair it’s unclear which cars will be eligible and even less clear the timeline on the upgrade availability.

Still it’s encouraging for those of us who would like a snappier performing interface, and just HAVE to have whatever racing game will replace Pole Position.

Not sure what the other benefits are, such as is it needed for feature such as Sentry mode or dash cam.

EVRider | 13 maart 2019

Dashcam and Sentry Mode require HW2.5, so an MCU upgrade wouldn’t make a difference. MCU2 came after HW2.5, so there are already cars with MCU1 that can use the dashcam and Sentry Mode.

SO | 13 maart 2019

This is awesome!

So rather than selling my ‘17 S90D, I can just replace the MCU and upgrade to HW 3.0 for free with FSD.

Then one day hopefully can swap out the battery for a larger pack and use my old one like a powerwall. No need to replace my current S since I like the silver, sunroof and leather ventilated seats.

That’s my plan anyway.

Boonedocks | 13 maart 2019

@SO | March 13, 2019
"This is awesome!
So rather than selling my ‘17 S90D, I can just replace the MCU and upgrade to HW 3.0 for free with FSD."

Based on how well our 2 Tesla's holding up, my S100D in particular 2 years old and 69k miles and minor issues, I will be happy to fork out a little for an MCU2 upgrade and have also purchased, at ordering, FSD so hopefully EAP/FSD will get a new lease on life as well. All much MUCH cheaper than the depreciation hit I would take.

RedJ | 13 maart 2019

@EV that’s a great point. I’d forgotten that MCU2 came after HW2.5

SO | 13 maart 2019

@Boonedocks - great!

craig.b.hummel | 13 maart 2019

Can someone tell me what all the abbreviations stand for?

SO | 13 maart 2019

HW - refers to Autopilot hardware. 1.0. Original Autopilot with 1 camera. 2.0 = 8 cameras and sonar. 2.5 = better cameras ?. 3.0 = faster Autopilot processor.

MCU - main control unit (i think that’s what it stands for) (large center screen on S and X). There are 2 versions (faster processor).

AP - Autopilot

EAP - enhanced Autopilot (lane change and navigate on autopilot)

FSD - full self driving

SO | 13 maart 2019

Not sonar. Radar

Bill_75D | 13 maart 2019

MCU might mean Media Control Unit | 13 maart 2019

MCU does mean Media Control Unit. I had mine replaced Aug 2018 as the old one would not install firmware updates (I have a 2014 P85D). The new MCU is no faster than the old one. I have LTE upgrade. I assume I have the newer MCU2 (Part #1458829-00-B).

Silver2K | 13 maart 2019


MCU2 is a 65" screen | 13 maart 2019

I made a large list of abbreviations and acronyms here:

HW2.5 has some additional reducancies, but AP functionally the same as HW2.0. HW2.5 does allow Sentry mode and Dashcams, not available in HW2.0.

inconel | 13 maart 2019

As mentioned it is probably the cameras in HW2.5 that enable Dashcam and Sentry (color, better resolution?). Upgrading to HW3 NN computer for FSD and MCU2 for faster display might not give Dashcam and Sentry, unless the newer cameras are also required for FSD.

EVRider | 13 maart 2019

My previous Model S had MCU1 and my new one has MCU2, and I'm not seeing a big difference in performance. Depending on what Tesla charges for the upgrade, it might not be worth it.

SO | 13 maart 2019

Based on MCU2 videos that I’ve seen, the screen response seemed snappier when flipping between control options and the maps. But maybe newer software has even slowed down MCU2.

RedJ | 13 maart 2019

MCU could also mean Marvel Cinematic Universe. But then you’d be in the wrong forum ;)

djjohnny110 | 13 maart 2019

@SO....i have a 3/17 ventilated seats!

How did you get them!!?!?!??

You think tesla has an option for swapping mine?

I only have heated. Hmmmm i thought it was only a performance option.

SO | 13 maart 2019

I ordered on election night in 2016. I thought, “oh hell, might as well....”. Click.

Living in Michigan, I didn’t really want it delivered in winter, so I delayed the production as much as possible (which was January) and then delivered in end of February. I think I just made the cutoff. And luckily delivery day was unseasonably warm at around 70.

Not sure they would swap out the seats now.

TBH, the ventilation doesn’t work that great but I think the perforated seats look kinda cool. If I’m wearing shorts, I can feel it on high. I just wish it blew out air instead of sucked it in. I think of it sucking in the sweat into the seats. Fortunately I usually precool the car, so it isn’t a big deal.

Rt. 66 | 13 maart 2019

I have a 75D delivered March 2018. How can I determine if I have MCU 1 or 2?

EVRider | 14 maart 2019

You can go to this site in the car’s browser to tell you which MCU you have:

PatientFool | 14 maart 2019

Isn't an MCU like $5k? I'm guessing any upgrade path is not going to be cheap.. I have a slower MCU and when i recently had a loaner with the newer MCU i didn't even notice. Sure, it's always nicer to have a snappier interface but if it ends up being as much as i suspect, i doubt i'll bother. it just doesn't matter much.

gregmiller1817 | 14 maart 2019

2014 MS P85+. When's the legacy upgrade kit available? Wouldn't that reward early adopters and boost resale values. Just think, your Tesla no longer gets old, just update hardware like software. Talking about upsetting the apple cart. That would really change the game.

jordanrichard | 15 maart 2019

Bump, to get ahead of the spam

zhangjunhuaz | 23 juni 2019

Any updates with MCU2 upgrade?

More and more features are mcu2 only now... MCU1 is really lagging behind

Ohmster | 23 juni 2019

^Can you elaborate on what features are exclusive to MCU2?

Tropopause | 24 juni 2019

Beach Buggy Racing. ^^^^^

inconel | 24 juni 2019

My MCU1 and I hate you! ^^^^^

zhangjunhuaz | 25 juni 2019

Also Chrome is on MCU2 as well | 25 juni 2019

@zhangjunhuaz - I thought Chrome was on all MCUs. The latest browser is faster on MCU1, but not as fast as MCU2, likely due to hardware. The agent string is the same now on both MCU1 and MCU2.

Ohmster | 25 juni 2019

So we have a performance improvement.
One app.
And one possible browser enhancement.
Is that it?

ionsphere | 25 juni 2019

Model S 17, MCU1, HW2.0. Somehow it allows enabling Sentry Mode but doesn't support Dashcam. Wondering how to view the videos then. Or are those "sentry events" going to /dev/null? | 25 juni 2019

Yep - hard to see paying $3K or so for MCU1 to MCU2. MCU2 also has the possibility of using your phone as a key like the Model 3, but this is not yet available even for those with MCU2.

zhangjunhuaz | 25 juni 2019

The new feature differences between MCU1 and MCU2 are growing and growing.
Tesla better to have a plan for current owner to upgrade
My car is built 3 months before the MCU2 is in production.

It’s possible, but is Tesla gonna do it? | 26 juni 2019

@zhangjunhuaz - They have said they are working on a MCU1 -> MCU2 retrofit, but after a year now, I wonder if they ran into some major problems and/or have abandoned it. It was never going to be a simple pull & replace as there is quite a bit more due to new antennas that don't exist in the MCU1 builds, and wiring harness changes.

For example, if they concluded they would need to charge $6K for the retrofit, they may figure so few owners would buy it to make it worth putting into production. I think at $3K they may get some traction perhaps selling 500 or so retrofits. In the scheme of things, even that may be too small of a quantity to bother with. Numbers and prices are purely my speculation so don't read too much into it. On the plus side, they may have stopped MCU1 production, so future MCU1 failures may make it necessary to replace with MCU2.

Jkohl | 28 juni 2019

Does anyone think that there could be a HW update for a Sept 16 P100DL to HW 3.O. I literally have everything I want on this car except the ability for FSD. Would gladly pay an upcharge to retrofit. | 28 juni 2019

@Jkohl - Sounds like your car is AP1, so no retrofit from Tesla. It would require new wiring harness, camera installations, AP processor installation (where there is no room under the dash), new ultrasonic sensors, new radar. One person, Jason Hughes, did take AP2 from a wrecked car and install it into his AP1 car. It's a huge project and requires quite a bit of software changes not approved by Tesla. I've not heard of anyone else doing it.

Boonedocks | 28 juni 2019

“ | They have said they are working on a MCU1 -> MCU2 retrofit”

The real problem is that Elon is the one that said that via a tweet. As much as I live Elon’s optimism, he was speaking technically that it was possible, and much as he does it’s from the heart but not likely to happen.

DBrohm | 29 juni 2019

I posted a month or so ago my SC said it's actively being developed.

luke | 23 juli 2019

In watching how A Better Route Planner performs on the MCU2 on Youtube, MCU2 seems orders of magnitude faster than MCU1. I have a 2017 AP2.0 MS, and using A Better Route Planner on the browser feels like what I remember using a 19.2k modem to be like. Even the keyboard slows down to a crawl.

MySin_AZ | 23 juli 2019

So, I have three years left on my 2014 S CPO...sounds like my best option is for the MCU1 to go kaput in the next 2 and a half years...

dborland | 8 september 2019

Of those that have had their MCU replaced, how long did it take the service center to do the work? I'm having mine replaced b/c it's dead and want to get an idea of how long they will keep the car since I have to drive 120 miles to the service center. | 9 september 2019

If the MCU is in stock, it's about 2 hours of labor. Now it may take longer as there are likely other customer cars in front of yours. I'd expect it to take a day in-service time. Perhaps they can prioritize your car if you are planning to wait for it.

akikiki | 25 februari 2020

Bump. Its been almost a year since this thread that started the conversation about MCU1 to MCU2 path.
And no solid news since.

packpike | 26 februari 2020

Our MCU1 is going bad in our MX (under warranty) and I've been told that there is no MCU1 to MCU2 upgrade. That being said, Tesla has a shortage of the MCU1's, so we're stuck waiting, hoping that ours doesn't completely die before it's available. I'm hoping that the shortage, which is currently being blamed on the coronavirus, is really due to the inventory being drawn down knowing that they'll be moving over to MCU2's, but that could just be wishful thinking.

barrykmd | 26 februari 2020

packpike | February 26, 2020
Tesla has a shortage of the MCU1's,

Why would this surprise anyone? The death of the MCU1 is like coronavirus - it's spreading. As Tesla no longer makes the MCU1, the supply of refurbs is tight, and only going to get worse.

Bill_75D | 26 februari 2020

It shouldn't get worse. Each time they replace one they gain another broken one to repair. They just need to repair them faster.

barrykmd | 26 februari 2020

Isn't there some law about car repairers being required to offer you the replaced part? What if people started keeping their old MCUs?

Silver2K | 26 februari 2020


You can ask for it, the is a $400 or $500 core charge. I wasn't thinking, I should have purchased my friend's old MCU and had it repaired as a backup.

Bighorn | 26 februari 2020

The average physician is not acquainted with core charges.

barrykmd | 26 februari 2020

Wish I knew about that when I was working. "If you want your old cornea back, it will be an extra $500..."

BH - Are you calling me an average physician?