Yet Another MCU Failure Post

[atc789]

I was just about to post about this exact issue! I have a 2014 Model S, out of warranty, pre-facelift, with AP1 and about 95,000 km. In retrospect, I was probably having issues for months (slow / sluggish interface and music streaming, internet connectivity dropouts, and voice commands not working) until two days ago my MCU completely failed on me. After trying (but failing) to reboot the MCU, the instrument cluster reset to imperial units, time zone was reset, and I lost all odometer and historical data.

I also had an A/C unit that was permanently on even when it was supposed to be turned off while in the parking lot at work. I had a sneaking suspicion so I went to check the car after a couple hours and noticed that I was losing over 10 km/h of charge. It probably didn't help that it was a really hot and humid day too.

Tesla Toronto confirmed my suspicions about the MCU failure. After complaining about the A/C drain on the battery, they asked me to bring the car to the service centre which was thankfully pretty close by and they were able to fit me in for a quick reset of the car. Took about 20 minutes and now the A/C now shuts off after I leave the car. The car is driveable but I have lost all turn signal functionality plus obviously all other functions controlled by the MCU. I noticed that although the turn signals don't work, the emergency 4 way flashers work. Why are these two functions separated even though they act on the same lights? Also charging rate is reduced to 8A (normally I get 40A) when plugged in at home.

Tesla Toronto is ordering me a replacement MCU which will come in possibly by the end of the week (the quote says a remanufactured MCU #1098010-99-H) for $1310 CAD. $1865 CAD in total including labor and tax. They quoted a 2 year warranty on the replacement. I saw posts about possible 3rd party replacements but since this is my daily driver, I want my car back up and running as reliably and as fast as possible... I was actually expecting to pay more for the replacement MCU but I'm glad that it looks like the costs are coming down.

In the fantastic 5 years that I've had this car, this has been the biggest and most inconvenient issue that I've had with the car....

Does anybody know if this remanufactured MCU has an upgraded eMMC for greater longevity compared to my original MCU? It really sucks to hear about this memory issue and I'm really hoping to be able to drive the car for several more years.

I see NHTSA complaints have been filed, but since I am in Canada is there anything I can do to add my voice to this issue?

Hey mcduck, which service center did you go to? Lawrence @ Railside Road? I'm likely going to need this done as well. Did they give you a price for MCU2 upgrade?

 

[badgirl]

Just to give you a taste of my experience. Over a week ago, after driving my 2015 Model S around half the day, out of nowhere the MCU goes black and doesn't come back. It just kept cycling as if I had rebooted and would get to the Tesla logo and go black again. I tried to reset it with the steering wheel controls but nothing worked. I couldn't turn on the radio and even turn on the a/c, and it was steaming outside. I made an appointment via the app saying in the description that I thought the MCU died. The earliest appointment was for 2 weeks out. I was bummed but I made the appointment.

I got a text from the Tesla Paramus dealer about an hour or two later saying that they looked at my appointment and wanted to help expedite my repair. They asked if I could bring it in the next day! I said yes and asked for a loaner since they might have to keep the car for a couple days because I thought it might be the MCU. They said they didn't have any loaners as of now but would give me $100 in Uber credits. I didn't feel comfortable taking an Uber during this pandemic and would arrange for my own transport but I told them to please let me know when a loaner was available. They agreed.

I went to the dealer first thing the next morning to drop it off. They said they agreed that it might be the MCU but will have to check to make sure. If it was, it would take a couple of days to repair maybe longer to get parts and repair it. To my surprise they were able to get me loaner since they knew the repair might take a couple days.

At about 5pm I get a text that the car was ready to be picked up! I texted back asking if it was the MCU and they said no, that the software got hung up. They were able to push the last update again and that fixed the issue.

I say all this to say, at least in my experience, you have to give them a chance to diagnose the issues. I know it can be frustrating to be in the dark but be patient.

I will say that I have had NOTHING but great experience with the Paramus dealership. They have been amazing.

Same happened to me, they needed to reinstall software , when I picked it up I was told that it may only last two weeks.
This is why I upgraded the eMMC chip because if the MCU dies again there's a good chance I can't get the vpn keys and Tesla will not reinstall them for you unless they install a new MCU.

 

[badgirl]

Hey mcduck, which service center did you go to? Lawrence @ Railside Road? I'm likely going to need this done as well. Did they give you a price for MCU2 upgrade?

I was given $2500 + labor for MCU2 upgrade or refurb MCU1 $1600 + labor.
I opted to remove the MCU 1 and have appleguru backup my data and install new eMMC chip cost was $500

 

[BlackMambaCoil]

SO I just got back from the service center. About 1 hour before the appointment they called me to go over some of the details, to which I had a bunch of questions lol. They told me they were planning on replacing the MCU with another MCU1. The service person told me the refurbished MCU1 would not run into the same issue, so I hope he is right about that. I am planning on opting for the MCU1 over the MCU2 since it'll save a grand and there aren't too many improvements since I'm still on AP1 with my 2015. The cost they gave me was about $1600 + labor. This was a verbal quote - I hope they hurry and add the quote in the app so I have a better estimate of how much it'll cost me. The downside is that its going to take 10 business days at the most since they haven't received the refurbished unit to replace it with yet. So here's to it coming in much sooner than anticipated!

 

[badgirl]

SO I just got back from the service center. About 1 hour before the appointment they called me to go over some of the details, to which I had a bunch of questions lol. They told me they were planning on replacing the MCU with another MCU1. The service person told me the refurbished MCU1 would not run into the same issue, so I hope he is right about that. I am planning on opting for the MCU1 over the MCU2 since it'll save a grand and there aren't too many improvements since I'm still on AP1 with my 2015. The cost they gave me was about $1600 + labor. This was a verbal quote - I hope they hurry and add the quote in the app so I have a better estimate of how much it'll cost me. The downside is that its going to take 10 business days at the most since they haven't received the refurbished unit to replace it with yet. So here's to it coming in much sooner than anticipated!

The refunb MCU1 is going to have the same Nvidia chip in it that is the cause of the failure.
Doing the removal of MCU, taking the Tegra board out and shipping it to someone that works on them, shipping it back and I reinstalling it and putting my car back together was Thursday night to Tuesday night including shipping both ways. I did temp put MCU back in the car without the Tegra card so I could still drive the car if need be.

 

[MP3Mike]

The refunb MCU1 is going to have the same Nvidia chip in it that is the cause of the failure.

The eMMC chip is not a Nvidia chip. (If I recall correctly it is a Hynix chip.)

 

[mcduck]

Hey mcduck, which service center did you go to? Lawrence @ Railside Road? I'm likely going to need this done as well. Did they give you a price for MCU2 upgrade?

Yeah I went to Lawrence Railside Road. I didn't ask for a formal quote for the MCU2 but they told me it would be over $1000 more than what they quoted me for the replacement MCU1. I opted for the MCU1 since I felt that the benefits I would get from an MCU2 wasn't worth the extra cost (I only have AP1 hardware too).

Wow, seems like people's experiences at different service centers is quite variable. I've had great experiences with Tesla Toronto Lawrence with prior issues and my current MCU issue. I emailed them Sunday night when I figured out I had the problem and they replied back first thing in the morning. Within 5-10 minutes from reading their reply, I was able to speak with the service rep. I got a formal quote from him via email less than 30 min afterwards. They rushed the replacement and today (4 days later) I dropped off my car for repairs and it's due for pickup sometime tomorrow! Unfortunately they didn't have any loaners available, got a $100 Uber Voucher to get home and recruited my wife to send me back to the service center tomorrow for pickup I'm quite impressed with their service so far, hoping everything goes smoothly tomorrow!

 

[mcduck]

Update:
I picked up my car from service yesterday and WOW what a difference with a replacement MCU, it's like a new car again! The interface is SO much more responsive! No more random connectivity dropouts (so far), voice commands are much more responsive now, Bluetooth functional again, and... even the crappy web browser works haha! Thinking back, I probably had mild symptoms of emmc failure well over a year ago but had chalked up most of my problems to the bloat from the new features and software added over the years...

Oh, and get them to upgrade it to LTE if you don't have it already; should be only another $120 or so.

Got LTE with my replacement MCU as well. I actually had LTE on my old MCU... had some issues with 3G connectivity several years ago and Tesla upgraded me for free as part of warranty repairs. Not sure if LTE just came standard with this replacement or if they just continued my access to LTE.

Hoping this new MCU will hold up for longer than my old one... I hope something comes out of the NHTSA complaints though. But for now overall I'm very happy with how quick and responsive Tesla Toronto was to my issues.

 

[dark cloud]

Update:
I picked up my car from service yesterday and WOW what a difference with a replacement MCU, it's like a new car again! The interface is SO much more responsive! No more random connectivity dropouts (so far), voice commands are much more responsive now, Bluetooth functional again, and... even the crappy web browser works haha! Thinking back, I probably had mild symptoms of emmc failure well over a year ago but had chalked up most of my problems to the bloat from the new features and software added over the years...


Got LTE with my replacement MCU as well. I actually had LTE on my old MCU... had some issues with 3G connectivity several years ago and Tesla upgraded me for free as part of warranty repairs. Not sure if LTE just came standard with this replacement or if they just continued my access to LTE.

Hoping this new MCU will hold up for longer than my old one... I hope something comes out of the NHTSA complaints though. But for now overall I'm very happy with how quick and responsive Tesla Toronto was to my issues.

I know all the American MCU's refurbs come with LTE, just wasn't sure about the CDN ones. Wonder why it is so much less than they pay in America, usually it is the opposite and we get hosed by more than the exchange rate alone.

Sounds like yours was rather crippled and on its way out. I didn't notice any difference with mine but I made sure I got it done before it failed.

 

[eschummer]

So first time for me. 2016 90D with about 116,000 km. My wife did a Spotify search and the screen went blank. Came back after a few tries, only to go blank again on the next music search (not Spotify). Stayed blank for a few tries, and eventually came back, very slowly. Should mention that due to the pandemic hadn't driven the car in quite a few weeks, so this was quite a surprise.

It acted fairly normally after the last restart, and it was OK for the rest of the drive. Didn't touch any music searches, but was able to get the phone to connect and play through bluetooth.

Haven't touched it since (three days), but am afraid what it's next failure mode will be.

Any advice? I'm not driving it much these days..

 

[badgirl]

Any advice? I'm not driving it much these days..

That what started to happen to mine , screen unresponsive, would work for a while and need to be restarted, or slow to wake up from sleep. Finally went black and won’t reboot (after coming out of a store) drove it home, no blinkers, no climate control (was98°), no early detection warning, headlights (if not on auto), no Bluetooth, no streaming music, and no tow mode. SC was able to bring it back to life after it was there all day.
After reading on the forum and finding out it’s a faulty chip, I opted to remove the MCU, take out the Tegra card and ship it to a member that can copy the data to a new chip better chip and install it and send it back (cost $500).
If Tesla looks at it they will replace the MCU, with either MCU1refurbished ($1600+ labor) or MCU2 ($2500+ labor).

The MCU failing is a safety hazard.
Please report it to https://www.nhtsa.gov

 

[BlackMambaCoil]

Well everybody! I got the text saying my baby is ready to be picked up (woo!) except that it can only be picked up during service center hours, which it opens on Monday morning (boo!). So hopefully, my saga will come to a close soon.

 

[markb1]

Well, yesterday, I got in my car and found the touch screen blank. Scroll wheel reboot didn't work. I even went as far as to pull and reinsert the MCU fuse. Seems like this could be the eMMC failure. I setup a mobile service appointment for Friday, then got a call from someone at Tesla (510 number), who, after hearing that I'd already tried to reboot it, rescheduled my appointment to the local service center on 8/3. Fortunately, I have the extended warranty for another six months, but it concerns me that he was talking like that had some tricks to get it working again. If the service center manages to extend the life of my MCU for six months, I'll be out of warranty when the eMMC fails for good. I'm also not thrilled that car has no turn signals!

Update on this. I just got my car back today, and Tesla Service managed to revive my MCU. That cost me a $200 deductible, but it apparently would have cost the same amount out of warranty (so says the service advisor). Here are the notes from the invoice:

Verified MCU blank on drive. Vehicle offline for 4 day. Performed hard reset and scroll wheel resets. Hooked up toolbox2 and attempted to perform offline auto install update. Update failed first attempt. Pinged gateway,CID and IC using Cygwin and found communication good. Attempted another offline auto install that passed. Performed second OTA to ensure mcu stays online. Function tested after repairs found system operating normally at this time.

 

[BobC]

My 2015 Model S 85D MCU1 just died at 69,977 miles. I have an appointment on 8/13. Hopefully, it doesn't take months to get it replaced.

 

[JPP]

FWIW I am in NoCA near the Fremont factory and have been waiting 6 weeks for a REMAN MCU1 to come into my local Servce Center--way backordered.

 

[vdiv]

It's like a doomsday clock ticking in my S70D, except there is no clock (and no ticking, just glitches). The MCU hasn't died yet because the ESA is still valid

 

[David29]

It's like a doomsday clock ticking in my S70D, except there is no clock (and no ticking, just glitches). The MCU hasn't died yet because the ESA is still valid

Unfortunately, your tongue-in-cheek comment is probably not valid. It seems more likely that your MCU memory will fail and you will indeed get a chance to exercise that ESA. Your car is 3 months older than mine but mileage also may be a factor (mine has about 50,800 miles). My MCU failed and was replaced about 3 weeks ago. I am assuming you actually hope yours will fail before the ESA is gone. In fact, from what I have read, it is possible mine could fail a second time while my ESA is still in effect. Which would not be so bad if it were not for the unpleasant conditions while it deteriorates and before it has reached the stage of being obviously done for....My advice is, try to get Tesla to set an appointment and order parts to replace it as soon as it is clearly getting bad, because otherwise you might face a long wait for parts or an appointment, based upon other people's experience.

 

[vdiv]

Tesla would likely not take proactive measures to order/reserve parts while it is still "functional" and while so many are waiting for one with their car dead. I have a maintenance scheduled for Friday, 82k miles on mine, so if I see a human being there I may ask. Not sure how much using the MCU has been a factor, I haven't much, don't stream music, don't use the browser, no games and farts, rarely use the navi.

We still don't know how Tesla refurbishes the replacement units, if the eMMC is replaced, with what kind/capacity, and how much change they've made in the software to limit the P/E cycles.