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Likely MCU Failure (MCU1 eMMC)

FPLPowered is very Pro with his car! We are working out some new processes. Anyone looking to work with us remotely please make sure to contact me before working on your car at all. I'm writing up a process so owners don't damage any parts of their car such as Windows, Battery, Dash (always a risk of damaging the aluminum trim.

Amen to damaged trim :( its so fragile
 
Just wondering, would it be possible to install a new emmc chip either blank or with the software you a re able to get out of it, and then drive down to Tesla and have them reinstall the software on the repaired MCU?

I guess, that when Tesla installs a "new" MCU it will be with the same type of emmc that will wear out in a few years as well and you will have to pay them 2100 usd every 2-3 years...

This thread has some really good information about what can and cant be done. And about Tesla restoring the files.

Preventive eMMC replacement on MCU1
 
Amen to damaged trim :( its so fragile

Replacing instrument cluster

May not help you if you have already damaged your trim but I found while replacing my instrument cluster that using an inflatable leveling tool that you can get a Lowes or Home Depot will push up the top of the dash without damaging the trim. I included my instructions on how I did that above along with the link to getting the tool at Lowes in the link above. Also have on that post the Youtube video I used to show how the tool works on our dashes.

I'm sure Tony will chime in on this but a few things to note before you attempt these types of MCU replacements remotely. Most of these should be common sense:

Roll down your windows! If you remove all power you won't be able to get into the car from the outside easily (I was going to keep my doors open but scared I would walk by and accidentally shut one)
Be comfortable with getting to the high voltage service loop and removing it
Be comfortable with removing terminals on the 12v battery
Have a 12v battery tender on hand as it might be a few days while the eMMC cards get shipped around
Don't work on any electronics on carpet or anything that can make static. I should have gotten an ESD mat to work on but I grounded myself
Have anti-static bags to ship the Tegra chip with

I was able to drive the car to the service center with the Tegra chip completely removed but I was not able to charge above 2 amps on my HPWC (normal for my single charger is 40 amp) and I did not have a schedule or PIN to drive enabled on my car. That doesn't seem to be the case with everyone but assume you won't be able to charge.

My car wouldn't move at all with the MCU completely removed.
 
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No Tesla will not restore a car with a "blank emmc" and I would doubt the SC will have the ability to restore from that level. I would imagine you would need to have a stellar relationship with the SC who would probably need engineering to assist in this type of restoration. The MCU you would buy from Tesla SC would be in a ready to install into car state. This would really require the stars to align for you to have this done.

So, i need to get my hands on a "ready to install" MCU to have that emmc card cloned, then they could restore it?
 
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Replacing instrument cluster

May not help you if you have already damaged your trim but I found while replacing my instrument cluster that using an inflatable leveling tool that you can get a Lowes or Home Depot will push up the top of the dash without damaging the trim. I included my instructions on how I did that above along with the link to getting the tool at Lowes in the link above. Also have on that post the Youtube video I used to show how the tool works on our dashes.

I'm sure Tony will chime in on this but a few things to note before you attempt these types of MCU replacements remotely. Most of these should be common sense:

Roll down your windows! If you remove all power you won't be able to get into the car from the outside easily (I was going to keep my doors open but scared I would walk by and accidentally shut one)
Be comfortable with getting to the high voltage service loop and removing it
Be comfortable with removing terminals on the 12v battery
Have a 12v battery tender on hand as it might be a few days while the eMMC cards get shipped around
Don't work on any electronics on carpet or anything that can make static. I should have gotten an ESD mat to work on but I grounded myself
Have anti-static bags to ship the Tegra chip with

I was able to drive the car to the service center with the Tegra chip completely removed but I was not able to charge above 2 amps on my HPWC (normal for my single charger is 40 amp) and I did not have a schedule or PIN to drive enabled on my car. That doesn't seem to be the case with everyone but assume you won't be able to charge.

My car wouldn't move at all with the MCU completely removed.


Thanks! this is pretty much what I would suggest.

Windows down for 2 reasons, so that you can open the front doors when there is no power, and 2 since there is no power the windows can not come down a little when opening an closing so there is risk of damaging/shattering the glass. They can probably be forced down when there is no power, but why risk damage?

Cover the aluminum dash trim with masking tape.

High voltage service loop. Removal is not hard, just need to get over the hurdle in your head, actually I don't believe this is listed in the service manual for MCU removal, It's not a bad idea, so if someone is very uncomfortable you can skip this step. I'll double check the manual to be sure...

When removing the trim pieces again, be careful not to nick the aluminum dash trim.

If you have not removed the trim before in the car, it's gonna take some force, A set of trim removal tool will help,
Panel/Trim Removal Tool Set 6 Pc
Trim And Molding Tool Set 5 Pc
both sets are handy, amazon also has similar, both are fine choices, basically any store that has similar tools are fine.

Things to do before removing your MCU/Terga or before it fails completely:
  • Disable Pin2Drive
  • Disable charging schedules
  • Set headlights to auto (I cant remember if headlights will come on)
Will add more to this list as I think of them

We have a few confirmed cases that the car is drivable without the terga. If you need to get around, do so at your own discretion. You will not be able to control your heat/cooling or change any of the settings listed above.
 
My thought exactly. Removing a daughter card has to be simpler, but if they don’t have serviceable sub-assembly in their system... time to create one. There had better be a revision indicator with the bad/good eMMC component. Are all the necessary bits local to the card though? If ROM with serial number(s) are not local to the card, that could be problematic. Then again, this could become big enough that it might be worthwhile to develop software to make the daughter card (or the whole MCU with a blank daughter card) prepared for installation in the field.
 
Is there a reason why Tesla doesn't just replace the Tegra board with the bad eMMC rather than a whole MCU which would reduce the cost of repair? I mean already do an LTE upgrade. I suppose they don't have an individual part for just the Tegra board?

They do but they call it a "refurbished MCU" Maybe they will in the future. For the longest time they only sold door handle new and whole... Finally they started selling the pivot gears and harness with microswitches... Until that time aftermarket door handle parts became available.. Maybe this is the cycle?
 
Well here's mine. They're currently working on it.
MCU estimate.PNG

Plus $139 for towing from Sacramento Supercharger to Tesla Rocklin. Couldn't charge from home, couldn't charge at Supercharger, they wouldn't budge regarding how the MCU should not die within 4yrs. Even though everyone says that when you get a replacement MCU that they give you a 4yr warranty. I smell lawsuit in the future since there will be lots of other dead MCUs.

Here's another wrinkle, I ask if I get to keep my old part and she said yes but had to check when I asked if there was a core fee. I was told that they are to keep the APN module and that will be destroyed. I'm texting back saying if you don't want people to use it, blacklist it. I don't want an incomplete backup MCU.

So pricing seems to be fairly consistent now but I'm still not happy they won't honor a part that goes bad that isn't considered a wear item like tires, brakes, wipers, etc. With all the articles bringing this issue to light, it will only get worse when people are forced to pay 2 grand to have a $15 replacement eMMC chip.

edit: Just noticed that @FPLPowered and @Muzzman1 have the same part number but mine is a newer revision.
 
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Scheduled for MCU replacement in my Sig on Monday. Service told me that they use remanufactured ones now, which are around $2500 vs $4k Cdn which lines up with others’ posts. They said remanufactured uses new parts except for the casing, etc. Not sure if that’s 100% true but hard to prove.

I’ve asked for my recently under warranty replaced lcd back to help subsidize my MCU replacement. They’re looking into a core charge or not - doesn’t make sense considering I’m paying 100% out of pocket now.

Assuming that works out, if anyone in the Toronto area wants a less than 1 year old LCD screen for a cheaper out of warranty replacement - please let me know.
 
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jake73

New Member
Nov 2, 2019
3
7
NW
Not sure if this has been mentioned before, but my situation has an interesting wrinkle. The MCU of our 2013 stopped accepting firmware updates about 18-20 months ago. It's an annoyance, but not worth $2k to replace it so we've just continued with it operating as it does. Tesla hasn't fixed the bug, so I figured if we need to replace it eventually, we might as well get as much time out of this one as possible. Apparently newer MCUs just have a bigger memory, so they are less likely to hit this issue.

Several months ago, the drive train started grinding so we took it to Tesla for replacement. They said it would be covered under warranty, but that we had to replace the MCU first. We didn't want to pay for the MCU but they said since the MCU wasn't covered, it would be our cost and we'd have to do this before getting the drive train replaced under warranty.

We are likely now in the position where we'll have to pay for the MCU repair / replacement and hope there's a class action lawsuit to retroactively reimburse us of this cost.

Won't ALL of these older MCUs need to be replaced eventually?
 
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Not sure if this has been mentioned before, but my situation has an interesting wrinkle. The MCU of our 2013 stopped accepting firmware updates about 18-20 months ago. It's an annoyance, but not worth $2k to replace it so we've just continued with it operating as it does. Tesla hasn't fixed the bug, so I figured if we need to replace it eventually, we might as well get as much time out of this one as possible. Apparently newer MCUs just have a bigger memory, so they are less likely to hit this issue.

Several months ago, the drive train started grinding so we took it to Tesla for replacement. They said it would be covered under warranty, but that we had to replace the MCU first. We didn't want to pay for the MCU but they said since the MCU wasn't covered, it would be our cost and we'd have to do this before getting the drive train replaced under warranty.

We are likely now in the position where we'll have to pay for the MCU repair / replacement and hope there's a class action lawsuit to retroactively reimburse us of this cost.

Won't ALL of these older MCUs need to be replaced eventually?
Yep. That's exactly what happened to mine first... Wouldn't update. They will all fail and then fail again in 4-6 years if they don't fix the root cause. Pretty sad.
 
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Yep. That's exactly what happened to mine first... Wouldn't update. They will all fail and then fail again in 4-6 years if they don't fix the root cause. Pretty sad.

I assume everyone is aware that Flash memory (which the eMMC is) does wear. Some Flash memory designs (usually for ids and such inside a microcontroller) are only specified at 100 write cycles. Designs like an eMMC would be designed for 100,000 writes or more. To deal with the wear issues they use wear leveling software. I've never been able to figure out where they keep the wear data so that it doesn't wear out, lol.
 

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