How common is replacing the MCU?

How common is replacing the MCU?

How often do you have to replace the MCU? How much is this?

acegreat1 | 28. August 2018

Hopefully never, about 2grand

Anthony J. Parisio | 29. August 2018

Over the past 4 years I have only read about 5 MCU replacements.

tes-s | 29. August 2018

I had mine replaced at about the 1 yr mark. There was a line down the middle of the screen.

ATCRomes | 29. August 2018

Dec 2013 Model S. Mine was replaced recently while it was in service. Tech noticed it was not responding well enough. Goodwill replacement, out of warranty. Car has about 48k on it.

Mickeymiller12 | 29. August 2018

Lucky you ATCRomes, they can be very expensive. Where did this happen?

NCC1701S | 29. August 2018

Gadget's (2015 85D) MCU was replaced in his second year because the soldered on SD card failed and the updates would not complete. It been fine since then. The SC told me that non warranty cost would have been about $4000.

S75RedRidingHood | 29. August 2018

if your model S is around end of 2016; there is a problem with yellow shade around the screen which is quite common and service center will take care of it for you by replacing it.

Sam_S | 29. August 2018

Mine was replaced at 3 years. It's $4k if you are out of warranty, so that one reason is good enough to get extended warranty once original expires.

Chunky Jr. | 29. August 2018

I have a 2013 P85 and I'm on my 4th MCU.
One had oozing from the LCD
One never came out of reset
One stopped responding to touch input intermittently
Hopefully the fourth time is a charm.

bill | 29. August 2018

I have the yellow line problem and Tesla is replacing the screen but not the MCU. I know that because I asked about paying extra to get the newer MCU and they said they only replace the screen not the whole MCU.

ATCRomes | 29. August 2018

@Mickey. Dedham Service in MA. It was in for repeated sunroof leaks and they threw it in as goodwill.

mybluetesla | 29. August 2018

My 2014 S85's MCU just died one evening almost three years ago. Thankfully replaced under warranty. I also heard it's about $4k out-of-pocket. I considered the Extended Service Agreement right before my 50k warranty expired, but considering the number of miles I've put on by that point I didn't bother since it seemed likely that such a high-priced component wouldn't fail on me during the ESA period (I'm at almost 93k now so my gamble was probably worth it).

Write-up here:

ggendel | 31. August 2018

My 2017 S MCU was replaced twice. The first time was when the sensors kept going offline. The second time a month later after I made an appt for a binding sun-roof. I just got a text that my part came in for the service. When I got there, they had an MCU to install. I think they saw my previous problem and thought it was the current one.

I've had my S for service more times than I want. I've had a mirror, several sensors, MCU (2x), replaced and the sun-roof worked on twice. All minor problems and the service was top-notch so nothing to complain about. The only problem is that the nearest service center is an hour away and I've yet been able to get their mobile service to me. I'll be going again next week as the screen developed the "1/2 inch yellow frame" issue so it will be replaced. Everyone there knows me by name. It's a good thing that my work schedule is flexible.

realestatejimmy | 19. April 2019

I had one replaced in 2017 when a software upgrade bricked the system. Then replaced it a second time April, 2019. Of course, the second one happened one month outside of warranty. :(

NOLEK SUM | 20. April 2019

S100D. Mine went at 10 mos, 5000 miles.

ebkbk24 | 29. April 2019

My MCU started pushing random buttons and immediately was sluggish. tried to reboot and the screen stayed black. it will supercharge but not charge at home. I understand it is out of warranty, but the MCU directly affects the ability to charge the battery with a home charger, and supercharging doesn't activate the fans now!!!

since the batteries are still under warranty for 3 years should i just drive it as it without regard for the battery as tesla will replace it as needed? i refuse to pay them for a refurbished unit when i can get a used one for a fraction of the cost on ebay. the only issue is it won't work without their programming.... or will it? i am not clear on this point.

Qwiksilver | 30. April 2019

2013 85S 71,000miles

Still have my original MCU. Works just fine. | 30. April 2019

@ebkbk24 - Most units on eBay are pulled from Salvaged cars. Some may be good, some may be bad. Doubt anyone selling them actually knows or has tested them.

Often the prices on eBay for Tesla salvaged parts are more than the same new part from Tesla, and are more likely to be down-rev versions. Check with Tesla the exact part price before buying something on eBay.

I don't know if used parts pricing is just poor knowledge by seller or a ripoff. Part of that is Tesla parts costs have come down over the years. I think the new MCU has dropped at least $1500 from 2014 pricing.

Sorry, but I don't know what problems you may have installing a salvage MCU into your car. You could stop by the service center and ask if they are willing to set the MCU to match your car. It might only be a small fee. Also be aware it's not all that easy to pull apart the dash to get to the MCU - clearly it can be done, but far from simple.

EmperorTytus | 30. April 2019

Feb 2015 MCU going strong here.

jordanrichard | 01. Mai 2019

2014, 152,000 miles, no issues with MCU apart from occasionally VC not working and the rare screen freeze, requiring a reboot.

Piotr12 | 04. Juni 2019

I think a software upgrade bricked the system,my Tesla is out warranty but the problem happen after download upg. From Tesla then why I have (We)to pay if Tesla send to our cars update with some problems, that looks like they broken ours cars and later we have to pay for repairs. Wake up,we have to do something with that | 04. Juni 2019

@wierzbowski - It is possible. The internal flash drive may be on its last legs, and any major writes to it may have caused it to go over the deep end. Any update would be a major write to the drive. Hard to say how long the flash memory should last, but it does have a finite lifetime. It is not easily replaced (soldered in place), so Tesla service replaces the entire MCU. If there was no update, the drive would have likely died anyway, perhaps within a month. Some of the parts may only last 5-7 years, while other owners may get 10-15 years out of it. There are so many variables, it's very hard to predict it's longevity. It will be partly time based and partly how many driving hours is done.

So perhaps it is better for it to die while parked, rather than on the road. Changes I've seen made in MCU2 make it look like it will last at least twice as long. Might be a good reason to do the MCU2 retrofit when it comes out. Unlikely though you can wait for the retrofit I have no idea when it will be available.

Lastly, someone has a third-party MCU repair service, but I don't know who it is. You'd have to remove the MCU, pull it apart and send a board to the company/person to repair it (replacing the flash drive). It partly depends if they can read some critical data off the drive. If not, a new MCU may be is required. MCU removal and repair are both non-trivial tasks and I gather you'd be without an operating car for a few weeks. For the DIYer, here's one post I found on the repair details:

Piotr12 | 05. Juni 2019 My Tesla will go to Tesla service then just wait what hapen ,but if MCU have to be replace then very bad because car have just 4 years | 05. Juni 2019

@wierzbowski - I assume you didn't get the extended warranty, which covers this. Still if this is the only major failure in the next 4 years, even though the MCU is costly, it's still less than the cost of the extended warranty, so you may be ahead of the game. Still no repairs would be even better.

diaretical | 05. Juni 2019

2013 P85 with 170,000 miles. Just spent $2400 replacing it last month after it went black and wouldn't come back on.

tes-s | 05. Juni 2019

@diaretical - did they replace it with MCU1 or MCU2?

Piotr12 | 05. Juni 2019

@diaretical - 2400$, I wonder what the cost will be in Europe

bill | 05. Juni 2019

There is a U-Tube video from a guy that buys salvaged Tesla's and is putting a model S guts into it. On one of the videos he says he has seen a lot of MCU failures and has diagnosed it to a memory flash card that is used for logging data for the developers. According to the video the logging is completely unnecessary and never used outside of the developers testing which would not involve a production car. He predicts that on average these failures happen at around the 4 year mark which is what you are experiencing.

While it may not be why your MCU failed but if it is it seems like you or anyone should have to pay for a failure that is caused by logging that Tesla should turn off in production cars,

bill | 05. Juni 2019

Sorry the previous post was suppose to say putting a model S guts into a ford sprinter van

diaretical | 05. Juni 2019

I believe they replaced it with a MCU2 since it know shows "LTE" where it indicates cell coverage.

diaretical | 05. Juni 2019


Piotr12 | 05. Juni 2019

@diaretical- my MCU was shows LTE where it indicates cell coverage too I You think that mean I have MCU2 on leate 2015 I dont think. Cost in EU 2950$ but I dont knows if MCU 2

Piotr12 | 06. Juni 2019

But any way problem with MCU it looks very bad,change almost most important part after 4 years because just stop working, unheard of by other manufacturers,should be a service action for MCU, because no one knows what will happen if it happens while driving

PrescottRichard | 06. Juni 2019

TeslaTap has this webpage for revealing which MCU you have- | 06. Juni 2019

@diaretical - Very unlikely MCU2, When Tesla does replace MCU1 in old cars, you get LTE as a bonus. It was a $500 upgrade option for MCU1 owners who only had 3G. I know, as I paid for the upgrade in my Jan-2013 S to get LTE!

AIA304 | 06. Juni 2019

Have you seen or heard of MCU missing errors in log files ? | 06. Juni 2019

@AIA304 - Nope, but if the MCU itself is failing (for any of a number of things in the MCU processor), the log files could be corrupted too.

AIA304 | 06. Juni 2019

Have on ours, when ranger was doing new key-fob programming and checking a summons issue, it’s when he left our car, I looked over at his laptop and observed our log file showing missing mcu errors.

DRFLGD | 08. Juni 2019

After having problems with my car connecting to WiFi since I got it, the module is now dead. The mobile tech said would be a "deep dive on the MCU to replace it." I wonder if it would be cheaper to just replace the MCU? If so, I wonder if I could finagle getting MCU2? | 08. Juni 2019

@DRFLGD - There is a module board that has the WiFi in the MCU. Tesla techs can replace this, but it does require pulling apart the MCU. I'm sure it will be far more expensive to replace the MCU, but worth asking what the price difference is (lower parts cost/more labor vs. higher parts cost/less labor). Ask about MCU2 retrofit, but no word that I've heard about it being available yet and no announced timeline - just that it is in the works :(

DRFLGD | 08. Juni 2019

TT: Yeah I plan on asking about a MCU2 retrofit. But expecting to hear it's not ready yet.

Piotr12 | 09. Juni 2019

My car is almost 4 years old and have 100000 km then warranty dont help me with MCU, if they have to replace MCU for new one, this new one will have guarantees for how long? If have

tes-s | 09. Juni 2019

My 2013 MCU1 has some sort of storage problem. Downloaded an update, and tries to install it every night for the past month but it fails. Anyone else seen this?

Tesla says they may be able to replace a memory card (sim?) or may have to replace the MCU. I'm going to see if I can hold out for a MCU2 upgrade.

Piotr12 | 09. Juni 2019

My Tesla was downloaded an update and just after ownloaded my central screen died, that was 3 weeks ago and now I am waiting in the queue to SC (10th July)my first Tesla but it looks like the last one , i think Tesla he kills his own cars

Piotr12 | 09. Juni 2019

My Tesla was downloaded a update and just after ownloaded my central screen died, that was 3 weeks ago and now I am waiting in the queue to SC (10th July)my first Tesla but it looks like the last one , i think Tesla he kills his own cars

Piotr12 | 10. Juni 2019

My car is almost 4 years old and have 100000 km then warranty dont help me with MCU, if they have to replace MCU for new one, this new one will have guarantees for how long? If have | 10. Juni 2019

@Piotr - I think the warranty on parts for vehicle out of warranty work is one year. It's been that way for other automakers for a long time, although some automakers only offer 90 days. There is no fine print on the Tesla work contracts that spell this out though. Perhaps someone else knows for sure.

Piotr12 | 22. Juni 2019

Now just waiting for new MCU, I dont know why but they not return the old one, i think if I will pay for new one I will keep The old

Tropopause | 22. Juni 2019

Just want to buy/upgrade to the MCU2 and forget about MCU1 on my S. Having a Model 3 (MCU2) and Model S (MCU1) has left me longing for the upgrade ASAP. | 22. Juni 2019

@Tropopause - Not an option (yet). Tesla is working on a MCU1 to MUC2 retrofit. Seem to be taking a lot longer than I'd expect. considering MCU2 was released 15 months ago. Makes me think there is something more complex than expected. MCU2 does use a new harness, new WiFi antenna and additional Bluetooth antennas. Those RF changes does mean it requires FCC certification, adding complexity to the task.