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Dead MCU Software 'Fix' vs EMMC Replacement by Tesla

hish747

Member
Feb 17, 2018
15
1
Connecticut
About a month ago my screen went dead. I was planning to send the board to Tony to replace the MMC and then I thought let me have Tesla take a look at it and see what they say. I drove it to the SC without turn signals and they were nice enough to give me a loaner Model S.

They told me to expect one of three things:
1. Software fix
2. Daughterboard replacement
3. MCU replacement

Yesterday, I got a response from them saying that they did a 'hard reset' and software restore and that the MCU was working. They charged me only the diagnostic fee and said the car was ready for pickup.

Given what we know about the emmc issue, I'm not at all confident in the software fix.
I wonder the following:

Have others have had a similar experience with Tesla recommending the software fix and whether it works for any reasonable amount of time?

Has anyone said to Tesla just replace the board and do we know if their board replacement involves better emmc memory or is it the same?

Just trying to figure out what to do before I pick up my car.

Thanks for any thoughts.
Hish
 

brkaus

Well-Known Member
Jul 8, 2014
7,722
6,253
Austin, TX
I’d love to hear the answers to this question. Have had my center screen crash a few times and for $500 I’d almost just prefer a new board.

I did read it’s a larger size, so hopefully last longer.

I have an appt to have HW3 installed on Monday.
 

DSolie

Pew Pew
Jul 2, 2020
284
629
Olympia, WA
I have an appt to have HW3 installed on Monday.

Well, HW3 will definitely put a nail in the coffin of the MCU1. I have HW3/MCU1 and she's laggy for sure. Not as bad as others have reported but it is noticeably slower. I'm just too stubborn to pay for an MCU2 when I am in the boat that Tesla shoudl just upgrade us for a reasonable cost if we have a HW3 slowdown.
 

MorrisonHiker

S 100D 2021.4.15
Mar 8, 2015
9,582
8,796
Colorado
About a month ago my screen went dead. I was planning to send the board to Tony to replace the MMC and then I thought let me have Tesla take a look at it and see what they say. I drove it to the SC without turn signals and they were nice enough to give me a loaner Model S.

They told me to expect one of three things:
1. Software fix
2. Daughterboard replacement
3. MCU replacement

Yesterday, I got a response from them saying that they did a 'hard reset' and software restore and that the MCU was working. They charged me only the diagnostic fee and said the car was ready for pickup.

Given what we know about the emmc issue, I'm not at all confident in the software fix.
I wonder the following:

Have others have had a similar experience with Tesla recommending the software fix and whether it works for any reasonable amount of time?

Has anyone said to Tesla just replace the board and do we know if their board replacement involves better emmc memory or is it the same?

Just trying to figure out what to do before I pick up my car.

Thanks for any thoughts.
Hish
Was the diagnostic fee $195? If a software 'fix' was all that was really needed, they wouldn't be offering the daughterboard swap or MCU replacement.

If it was me, I would've just told them to skip the diagnostic and to just replace the daughterboard for the $3xx, including labor.
 
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brkaus

Well-Known Member
Jul 8, 2014
7,722
6,253
Austin, TX
Well, HW3 will definitely put a nail in the coffin of the MCU1. I have HW3/MCU1 and she's laggy for sure. Not as bad as others have reported but it is noticeably slower. I'm just too stubborn to pay for an MCU2 when I am in the boat that Tesla shoudl just upgrade us for a reasonable cost if we have a HW3 slowdown.
I'm too stubborn to give up FM. Local stations we listen to frequently are not on Tunin. And some places in Texas don't have cell signal.

I can deal with slow interface. The car still drives fast. I just don't want to get stranded.
 

hish747

Member
Feb 17, 2018
15
1
Connecticut
Was the diagnostic fee $195? If a software 'fix' was all that was really needed, they wouldn't be offering the daughterboard swap or MCU replacement.

If it was me, I would've just told them to skip the diagnostic and to just replace the daughterboard for the $3xx, including labor.

Very close. The diagnostic fee was about $185 but I didn't have a choice of not doing it since they needed to do the diagnosis in order to determine what the issue was. They discouraged replacing the daughterboard by saying it takes 3 weeks to get it bla bla bla...and I just wanted my car back.

What is HW3? Is that the new daughterboard chip?
 

hish747

Member
Feb 17, 2018
15
1
Connecticut
The software fix worked for a whole month for me before it died again. I would recommend you do the daughterboard replacement if you want to keep MCU1.

That's funny. When the SC rep told me that it was the software fix, "I said do you warranty the fix? I don't want to here in another month with a dead screen." He said, since it was just a software update, there's nothing to warranty since everything is working. Nonsense to be sure. I ended the call by saying that I will expect courtesy (free) service if this fix proves ineffective; which I'm fairly confident it will.

Has anyone ever taken a car with a dead MCU had Tesla agree to just replace the daughterboard without doing any other work?
 

MorrisonHiker

S 100D 2021.4.15
Mar 8, 2015
9,582
8,796
Colorado
That's funny. When the SC rep told me that it was the software fix, "I said do you warranty the fix? I don't want to here in another month with a dead screen." He said, since it was just a software update, there's nothing to warranty since everything is working. Nonsense to be sure. I ended the call by saying that I will expect courtesy (free) service if this fix proves ineffective; which I'm fairly confident it will.

Has anyone ever taken a car with a dead MCU had Tesla agree to just replace the daughterboard without doing any other work?
Many have been able to get the daughterboard replaced and didn't have to pay the diagnostic fee. Check out this thread: Tesla now repairing MCU1 with a new Tegra card for $500

If someone goes in and knows to request the daughterboard be replaced, I believe they have been able to avoid the diagnostic charge. It's unfortunate they don't apply the diagnostic fee toward the price of the daughterboard replacement labor.
 

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