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MCU1: Black center screen / mcu failure caused by a faulty navigation MicroSD card

DannyDrive

New Member
May 4, 2021
3
0
Germany
Does my Facelift Model S from 06/2016 with original MCU (MCU1) also have the MicroSD card with navigation data?

Because I also had some issues regarding navigation system in the past few days/weeks. It often doesn't load and only shows the message that the navigation system is initializing.

So can I take the original MicroSD out of my MCU, copy the data onto a new 32GB MicroSD, stick it in my MCU and the problems should be solved? :)
You need a Linux OS.

Where you from in Germany?
 

LuckyLuke

Model S P90DL
Dec 14, 2011
2,285
607
Eindhoven, The Netherlands
Now I'm in doubt about my prior statement on the MCU1.5 units. If your MCU1.5 still uses the external MicroSD card for maps instead of the internal secondary emmc then yes you can replace the current/old with a new card ofcourse.

1. I have not tested this but since there is quite some reading done while calculating a route then the answer is yes: replacing the card with a better/recent one will improve the performance a little bit. I would not expect a miracle though ;)
Don't forget the Google map tiles that are displayed on the main screen are real-time downloaded over the air (and cached on the primary emmc). Only the route calculation itself is done from the microsd (or secondary emmc) maps data.

2. There is a file on partition 3 of the primary emmc (this partition is mounted as /var) at (/var)/etc/maps-device , this file content is either "/dev/mapsSD" or "/dev/mapsMMC". The former tells the system to read the nav data from SD, the latter from the secondary EMMC.
In your case I expect it to say SD since you tested this by taking the card out.
There is another file on the primary emmc called (/var)/etc/map-updater/BANK_(A or B).size , this file tells the system the size (in bytes) of the sqfs image and wether it is located on partition 1 (bank A) or partition 2 (bank B).

3. Yes. There are always 2 partitions. Since version 2019 the maps are in squashfs format. So I assume your partition 1 is either the EU-2019.20-10482 or the EU-2019.21-12489 sqfs image. Your partition 2 is either empty or it contains some older maps (which used to be stored in ext3 fs).

I can send you a 16GB image to write to the new card but I need to know first which map version you have is it 2019.20 or 2019.21 ?
(I put the same version map sqfs on both p1 and p2 so it does not matter if your .size file says the maps are located on bank A or B)
However, if your current microsd card is still readable you don't need my image at all, you can just make a 1:1 bitcopy from the current card.
 
  • Helpful
Reactions: oaito

scaesare

Well-Known Member
Mar 14, 2013
8,280
13,365
NoVA
Interesting... I noticed yesterday that my map tiles seemed rather slow to update when doing a map zoom.

Seeing as how my dash is still disassembled and my MCU only has a couple of screws holding it in after my eMMC swap while I decide what to do with my goo-leaking screen, maybe it's time to clone my SD card....
 

slainla

Member
Jul 25, 2018
126
83
Los Angeles
It can. But if you current card is still somewhat alive why not just make a 1:1 bitcopy of it to a new card? Then you don't need to bother with partitioning etc.

Thanks so much! I finally got to trying it out today and this method worked like a charm. I used AOMEI Backupper Standard (free software) on a PC and selected the clone feature with sector-by-sector copy option.

The first go around failed after 80% or so because it couldn't read a sector. However I tried again and it worked. I proceeded to insert the SD card and power the MCU back up. It booted up fine the first time but was laggy in the menu screens and subsequently froze while calculating a route. I reset it with the scroll wheels and the menus and navigation seems to work fine without any noticeable lag.

However, the audio completely stopped working ever since I repowered the MCU with the new SD card (previously powered off by removing the the fuse while I copied the SD cards). The power off and scroll wheel resets didn't fix the audio issue but I'll research and try again tomorrow.
 
  • Informative
Reactions: oaito and Droschke

Zuikkis

Member
Aug 19, 2020
233
271
Finland
A friend of mine has this problem on his car.. MCU is still usable, but navigation doesn't work because it can't find maps. Tesla blamed it on 3rd party eMMC repair, and offered to reformat and reinstall the navigation card for 220€! 😳 Still keeping the old card!

So, what's exactly needed to get it fixed? New 16GB card? Is it possible to just install properly partitioned empty card, does the car load maps from the net then?

Does anyone have a Linux script which would create correct empty card? In @LuckyLuke 's post there's a mention of "nav-sdcard-format.sh" but I understand this is something in the car software. Is it possible to create a standalone version that could be run on a Linux PC?
 

David29

Supporting Member
Aug 1, 2015
2,187
1,801
DEDHAM, MA
Hi all. Just a informative / warning message from me :)

There is now a new, until now largely unknown, reason for getting a full black center screen on a first generation MCU1.0 found on cars up to and including 2015. This report does not cover the newer 1.5 MCU found in 2016 and newer cars, however a similar problem could occur in that system as well.

In the past weeks I have seen some cars where the EMMC was already replaced before (most by 3rd party, but also one that was replaced by Tesla).
The problem: the main screen went black again, and a error message pops up in the Instrument Cluster "center screen not functional". Exactly like you would see when the EMMC chip fails.
Some cars had been to Tesla Service Center already for this problem. At the Tesla Service Center they usually diagnosed it as "MCU needs to be completely replaced" and one customer was even told the problem was caused by "third party EMMC repair". Lucky for these customers they contacted me to find out what the problem was exactly.

The car owners all reported that the problems started with navigation issues, slow calculating routes, nav icon keeps spinning, new maps trying to download over wifi, etc. After scroll-wheel rebooting the MCU it stays black. Appearing almost exactly when EMMC chip is failing.

I have investigated these cases and they are all related to a failing navigation maps MicroSD card (this 16GB MicroSD card is located on the MCU1.0 mainboard). Apparently when the navigation card dies this can cause the entire system to crash and not even start anymore (not even when power cycling the mcu).
Even when the MicroSD card was completely removed or replaced the system would still not start and will still give a black screen. Huh!?
This was all on 2013-2015 MCU1.0 cars, newer MCU1.5 cars from 2016 and up have replaced the MicroSD card with a internal/soldered EMMC chip for the maps.

Anyway: a dead/corrupt MicroSD card can prevent the system from starting up completely. The Tegra computer will boot in what that is called "Recovery" mode and it will also write some changes to the boot environment stored on the NOR chip which is located on the Tegra module (this Spansion NOR chip contains the bootloader, environment and kernel images). This change prevents the Tegra from booting to normal mode. Wut?!

To fix this problem you will need to do several things:
1) Replace the MicroSD card with a new one (16GB recommended, but can be larger as well)
2) Fix the environment on the NOR chip on the Tegra module (mtd7 partition, swap boot bank, fix fail count)
3) Partition the new MicroSD card with the correct partitions (can use nav-sdcard-format.sh for that)
4) Install the correct navigation maps on the MicroSD card (EU maps are about 8GB in size)
Step 1 can be done easy by swapping the card in the MCU (accessible from the side of the MCU housing)
Step 2 is way more complex and only possible when you have full read/write access to the NOR chip. Most repair shops that deal with EMMC repairs will be able to do this.
Steps 3&4 can be done on a (Linux) pc if needed, but can also be done on the MCU itself (need root access for that).

If you go to Tesla with this problem they will most certainly tell you that "The entire MCU needs to be replaced", or even throw in a "Problem caused by 3rd party repair" excuse. All that for a cheap MicroSD card...

Considering these cars are getting older, the chances are increasing that more owners with MCU1.0 cars will eventually face a failing navigation MicroSD card.
Conclusion: If you see reports on black screens then it could be a navigation MicroSD issue. Even on cars that already had the EMMC chip replaced (by Tesla or by third party).

If you face any MCU1 related issues and don't want to go to Tesla feel free to PM me for help.

What if the EMMC repair was the earlier version, in which the entire MCU is replaced? Would this same problem occur? Do you know if Tesla did anything to refresh or replace the navigation SD card on the replacement MCU?
My MCU was replaced about a year ago, presumably with a rebuilt one (whatever that might mean). It has worked more or less correctly since then, but just in the past week or two, I have had two instances in which the touch screen would not respond. E.g., i was trying to change channels when listening to a podcast on Slacker. The voice control worked to bring up the channel i wanted, and the screen worked normally later. But i do not recall having an unresponsive screen before, even when the eMMc was failing the first time.
 

slainla

Member
Jul 25, 2018
126
83
Los Angeles
Thanks so much! I finally got to trying it out today and this method worked like a charm. I used AOMEI Backupper Standard (free software) on a PC and selected the clone feature with sector-by-sector copy option.

The first go around failed after 80% or so because it couldn't read a sector. However I tried again and it worked. I proceeded to insert the SD card and power the MCU back up. It booted up fine the first time but was laggy in the menu screens and subsequently froze while calculating a route. I reset it with the scroll wheels and the menus and navigation seems to work fine without any noticeable lag.

However, the audio completely stopped working ever since I repowered the MCU with the new SD card (previously powered off by removing the the fuse while I copied the SD cards). The power off and scroll wheel resets didn't fix the audio issue but I'll research and try again tomorrow.
My sound issue was solved by reconnecting the black MCU plug on the bottom right that somehow got disconnected during removal of the SD card. I literally checked all fuses from boxes 1-3 then realized it’s gotta be a loose connector. I didn’t see it at first since there are like 10 connectors and it was covered by all the other wires when accessing it from the passenger seat.

Just some observations and things I learned along the way:
  1. The original micro SD card is a SanDisk ultra 16gb class 4. The total capacity is 14.84gb
  2. I bought a Gigastone high endurance 16gb card from Amazon and the total capacity is only 14.76gb so I couldn’t perform a clone since the capacity is too low.
  3. I had an Adata class 4 that registers 14.84gb and it worked fine after cloning.
  4. I also tested with a Kingston u1 32gb micro SD and that cloned fine and worked on the MCU. After cloning it shows the two partitions with ~14gb unallocated.
  5. Tesla charging $20 for a new SD card and $195 for labor which is equivalent to 1 hour base labor, seems fair. but it’s really not that hard of a job especially with online resources available like this thread.
 

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dark cloud

Active Member
Apr 14, 2018
1,946
2,196
BC

Zuikkis

Member
Aug 19, 2020
233
271
Finland
The expensive microsd cards have improved write durability. Pretty much the same thing as the MCU1 eMMC problem, continued writes eventually make the memory wear out.

However if I'm not mistaken, this navigation microsd is only written when maps are updated? So it's very rare. I guess you are wasting money if buying extremely durable card? Reads do not wear the card.

That said, I just bought a Sandisk High Endurance 256GB card for my dashcam, and it was only 49€ .. So I guess 16GB or 32GB high quality card shouldn't cost too much, if you like to play it safe.
 

DannyDrive

New Member
May 4, 2021
3
0
Germany
Now I'm in doubt about my prior statement on the MCU1.5 units. If your MCU1.5 still uses the external MicroSD card for maps instead of the internal secondary emmc then yes you can replace the current/old with a new card ofcourse.

1. I have not tested this but since there is quite some reading done while calculating a route then the answer is yes: replacing the card with a better/recent one will improve the performance a little bit. I would not expect a miracle though ;)
Don't forget the Google map tiles that are displayed on the main screen are real-time downloaded over the air (and cached on the primary emmc). Only the route calculation itself is done from the microsd (or secondary emmc) maps data.

2. There is a file on partition 3 of the primary emmc (this partition is mounted as /var) at (/var)/etc/maps-device , this file content is either "/dev/mapsSD" or "/dev/mapsMMC". The former tells the system to read the nav data from SD, the latter from the secondary EMMC.
In your case I expect it to say SD since you tested this by taking the card out.
There is another file on the primary emmc called (/var)/etc/map-updater/BANK_(A or B).size , this file tells the system the size (in bytes) of the sqfs image and wether it is located on partition 1 (bank A) or partition 2 (bank B).

3. Yes. There are always 2 partitions. Since version 2019 the maps are in squashfs format. So I assume your partition 1 is either the EU-2019.20-10482 or the EU-2019.21-12489 sqfs image. Your partition 2 is either empty or it contains some older maps (which used to be stored in ext3 fs).

I can send you a 16GB image to write to the new card but I need to know first which map version you have is it 2019.20 or 2019.21 ?
(I put the same version map sqfs on both p1 and p2 so it does not matter if your .size file says the maps are located on bank A or B)
However, if your current microsd card is still readable you don't need my image at all, you can just make a 1:1 bitcopy from the current card.
1. Got it 👌:)

2. I see thats a great information to know. I need to check that. How or with which tools can I connect with the MCU1 to see the content on primary or secondary EMMC?

3. You are right about partition . Looks like something is wrong with the 1st partition on my original MicroSD card. Its not reading the former partition 1 with the EU-2019.20-10482 files on the MicroSD card. MCU is reading the old EXT3 partition 2 with the old EU-2018 map files.
 

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