2013 MS 85 upgrade to MCU2 then HV battery problem

[Espi2451]

UPDATE: So far so good. I e noticed the supercharging is faster. It does slightly use more energy than previous. I’d say I get between 2-2.5 miles per 1%. Should be about 3miles. However, I do have the MCU2 so that may be taking extra energy. Starts up quick. No major issues since It broke down on me the same day! Wife got the courage to use it again . Curious how these 1014116-00-C packs will fare. Still thinking about selling before the warranty expires…but who knows.

 

[ddb1001]

UPDATE: So far so good. I e noticed the supercharging is faster. It does slightly use more energy than previous. I’d say I get between 2-2.5 miles per 1%. Should be about 3miles. However, I do have the MCU2 so that may be taking extra energy. Starts up quick. No major issues since It broke down on me the same day! Wife got the courage to use it again . Curious how these 1014116-00-C packs will fare. Still thinking about selling before the warranty expires…but who knows.

I saw a 2017 MS 100D with FUSC and only ~70k miles for $57k. Great deal if I knew the company wasn't going to drop a software update that would reduce the charge rate or make me cough up $20k to fix something. I'm selling mine after all the battery issues. Not hearing good things about the 90D or 100D - this too.

 

[geordi]

295 miles on a 90kWh pack is exactly where I was just before they nerfed my pack right after the MCU2 upgrade, and then after they un-forked it when the whole thing blew up on them PR-wise.

You got a good setup, b/c you have a 4 year warranty. Mine was replaced under warranty, which means that since they ran out the clock while it was being replaced.... If your failure had happened to me, they probably would have smiled and said "now you owe us for the full price"... Parts replaced under warranty are ONLY covered until the end of that same warranty period.

They are VERY sneaky about getting every dime out of the customer they can.

 

[Wattsgas]

lI dropped my car off to sunnyvale sc while still under the 8 year warranty. I had asked to check the DU from DU and the degredation on HV range and supercharging issue. They replaced DU under warranty and said my HV is healthy. knowing this, I proceeded to replace my leaking mcu and IC screen by upgrading to MCU2. 2 drives later I get the BMS u029 error code. I came back and they will not cover anything and adamant about me to shoulder the cost. I spoke to SC manager, regional manager and tesla corporate. They will not stand by their word and not cover anything.

 

[Wattsgas]

lI dropped my car off to sunnyvale sc while still under the 8 year warranty. I had asked to check the DU from DU and the degredation on HV range and supercharging issue. They replaced DU under warranty and said my HV is healthy. knowing this, I proceeded to replace my leaking mcu and IC screen by upgrading to MCU2. 2 drives later I get the BMS u029 error code. I came back and they will not cover anything and adamant about me to shoulder the cost. I spoke to SC manager, regional manager and tesla corporate. They will not stand by their word and not cover anything.

Meant I had asled to check DU for noise. They will stand by their word that battery was good and it was bad luck it died 2 drives later

 

[Espi2451]

Meant I had asled to check DU for noise. They will stand by their word that battery was good and it was bad luck it died 2 drives later

Sorry to hear that. Eerily similar to my original problem. Did they tell you what the problem was? My explanation was that the new MCU2 has capabilities of identifying problems with the battery that MCU1 can’t identify. It’s probably BS, but that’s what they gave me. It can’t be “bad luck” Too much of a coincidence

 

[geordi]

They are SO shady it should be illegal. The MCU upgrade has nothing to do with the battery manager, but as part of the process the car is rebooted - sometimes that makes the BMS recalculate things.

I'd have a talk with 057 or since you are in Cali, there are several third parties out there who I can't remember right this second - BUT there are resources who can read the BMS and sort out which specific modules might need replacement, that would get you back on the road a LOT cheaper than those pirates at the SC.

 

[maximizese]

They are SO shady it should be illegal. The MCU upgrade has nothing to do with the battery manager, but as part of the process the car is rebooted - sometimes that makes the BMS recalculate things.

I'd have a talk with 057 or since you are in Cali, there are several third parties out there who I can't remember right this second - BUT there are resources who can read the BMS and sort out which specific modules might need replacement, that would get you back on the road a LOT cheaper than those pirates at the SC.

Oh man, don't make me defend the horrible SC. While I've had a 50:50 experience at my local SC, they aren't even equipped to fix the battery or swap modules. Most are only capable of removing and installing the battery pack and external components such as HV contactors. Therefore, they can only perform and parrot what corporate allows them to do which is the least economical path for the customer but allows them to assure a working solution.

If I had a bad battery pack, I would certainly try my luck with 3rd party solutions to fix/replace a few components at a fraction of the replacement pack cost. But I'm holding out for the day when a 3rd party develops an improved pack or drive unit; hoping we're less than 8 years off from that.

 

[geordi]

But if you suddenly have a BMS code, it isn't going to get better and there's a way-higher-than-zero chance it will decide to brick the car at a REALLY inconvenient time or place.

 

[howardc64]

lI dropped my car off to sunnyvale sc while still under the 8 year warranty. I had asked to check the DU from DU and the degredation on HV range and supercharging issue. They replaced DU under warranty and said my HV is healthy. knowing this, I proceeded to replace my leaking mcu and IC screen by upgrading to MCU2. 2 drives later I get the BMS u029 error code. I came back and they will not cover anything and adamant about me to shoulder the cost. I spoke to SC manager, regional manager and tesla corporate. They will not stand by their word and not cover anything.

I've also read 2x batteries bricking during the transfer process on car sales (reset and ownership transfer) Not really sure whats going on. Maybe coincidence? Maybe something more stressful on the battery while at SC? It seems SCs like to charge to 100% thinking that does something like "rebalancing"? I'm actually studying rebalancing ATM. Wondering if firmware updates like pumpgate (pushes owners to stay < 80%) keeps on narrowing the operating window and limiting BMS's full profile view of battery pack.

Here is the FB group with these 2x battery bricking cases. I think also read recent posts of firmware updates bricking the battery?

Tesla BMS_u029 | Facebook

 

[geordi]

I've also read 2x batteries bricking during the transfer process on car sales (reset and ownership transfer) Not really sure whats going on. Maybe coincidence? Maybe something more stressful on the battery while at SC? It seems SCs like to charge to 100% thinking that does something like "rebalancing"? I'm actually studying rebalancing ATM. Wondering if firmware updates like pumpgate (pushes owners to stay < 80%) keeps on narrowing the operating window and limiting BMS's full profile view of battery pack.

Here is the FB group with these 2x battery bricking cases. I think also read recent posts of firmware updates bricking the battery?

Tesla BMS_u029 | Facebook

I don't want to put words in @wk057 's mouth here, but I remember him saying something about how running the battery down to a very low SoC and then charging all the way up to full will cause the BMS to recalculate. Firmware updates or a hard reboot may also trigger this, so it isn't that they caused the error.... Just that it was already there, but the BMS hadn't tripped over it yet.

 

[NV Ray]

I don't want to put words in @wk057 's mouth here, but I remember him saying something about how running the battery down to a very low SoC and then charging all the way up to full will cause the BMS to recalculate. Firmware updates or a hard reboot may also trigger this, so it isn't that they caused the error.... Just that it was already there, but the BMS hadn't tripped over it yet.

For your consideration from @Recell - 2014 85 HV Battery BMS_u029 error 1 month out of warranty and after a recent OTA update, Who else?

 

[ZigisK]

MCU1 -> MCU2 doesn't change ANYTHING with regard to the BMS... So this ^ is complete BS. The MCU has nothing whatsoever to do with battery management. Never has.

Either they don't actually know what they're talking about, are being given incorrect information to start with, or are just making things up to try and sooth the customer. Bad look regardless.

Not true...there is nasty surprise in lastest software updates, once the mcu2 soft is changed back to old 2021 something version, car will be back as before upgrade, the problem in there is imbalance due leaked capacitors. Older versions was not so strict and used software that calculate theoretical walues for damaged bmb. Have fixed and tested myself this, the hardest part is to remove and dissasemble.

 

[howardc64]

I don't want to put words in @wk057 's mouth here, but I remember him saying something about how running the battery down to a very low SoC and then charging all the way up to full will cause the BMS to recalculate. Firmware updates or a hard reboot may also trigger this, so it isn't that they caused the error.... Just that it was already there, but the BMS hadn't tripped over it yet.

Yes, this is what I plan to do. Here is an interest article that explains all this

Tesla battery management system (BMS) calibration (tesla-info.com)

I'm curious if possible to sit at each SOC % for 5-6 hours without load demand so BMS can confidently gather the necessary knowledge on battery SOC profile. Recharge 12V will take place periodically. Pump gate runs pumps+chiller for a very long time > 80% SOC.

Anyway, I'll be exercising this... easy to imagine will take awhile. At least a couple of weeks haha.

 

[howardc64]

Not true...there is nasty surprise in lastest software updates, once the mcu2 soft is changed back to old 2021 something version, car will be back as before upgrade, the problem in there is imbalance due leaked capacitors. Older versions was not so strict and used software that calculate theoretical walues for damaged bmb. Have fixed and tested myself this, the hardest part is to remove and dissasemble.

Can you explain more? Which caps on the BMB? Got a picture which ones go bad? What do they do? on high power or low power logic circuits?

Electrolytic caps are key failure components and always from leaking/bulging. Even surface mount (SMT) caps are usually the first to die on boards (high power FETs too) So much so there is a repair forum called badcaps.net haha. Countless electronics even < 5 years old gets tossed out due to PSU electrolytic cap and SMT cap failures. For electrolytic caps, caps can be under stressful operating condition and lower quality. Japanese caps are #1 but tons of caps seems to be shifting towards Chinese manufacturers with system manufacturing there.

 

[Cheese Guy]

I've also read 2x batteries bricking during the transfer process on car sales (reset and ownership transfer) Not really sure whats going on. Maybe coincidence? Maybe something more stressful on the battery while at SC? It seems SCs like to charge to 100% thinking that does something like "rebalancing"? I'm actually studying rebalancing ATM. Wondering if firmware updates like pumpgate (pushes owners to stay < 80%) keeps on narrowing the operating window and limiting BMS's full profile view of battery pack.

Here is the FB group with these 2x battery bricking cases. I think also read recent posts of firmware updates bricking the battery?

Tesla BMS_u029 | Facebook

I'm guessing on ownership transfers the car is "wiped" and reset back to default triggering a deep diagnostic. Shortly after and with the new owner you get error message about the newly detected deficiency in the battery. Probably a good idea to do a wipe and reset of the car a few months before your warranty runs out to see if any faults are detected earlier rather than later.

 

[wk057]

Not true...there is nasty surprise in lastest software updates, once the mcu2 soft is changed back to old 2021 something version, car will be back as before upgrade, the problem in there is imbalance due leaked capacitors. Older versions was not so strict and used software that calculate theoretical walues for damaged bmb. Have fixed and tested myself this, the hardest part is to remove and dissasemble.

This makes no sense.

It's the newer versions that have workarounds for broken cell sense connectivity. The older versions completely choke and shutdown in the same conditions since it just assumes the cell group is critical dead.

There's no electrolyte in any of the capacitors on the sense boards on the modules. They're all ceramic SMT caps. Nothing to "leak". There's some SMT electrolytic caps on the master BMS board, but they're actually way over spec'd and of high quality. I've yet to see any that have failed, even in the oldest packs, and I really don't expect to see any failures caused by these.

That said, with moisture ingress these module boards can corrode, and one of the lowest components on the board is a cap that corrodes, but it's just because it's the lowest component (others around it also corrode). But there's nothing to leak. This is pretty much the failure the newest firmware is designed to work around. As the sense connection to brick6 fails, the firmware uses the bulk voltage to calculate the value of the "missing" group. Older firmware can't do this and will just shutdown the car or limit capacity. See my writeup about this.

 

[ddb1001]

They are SO shady it should be illegal. The MCU upgrade has nothing to do with the battery manager, but as part of the process the car is rebooted - sometimes that makes the BMS recalculate things.

I'd have a talk with 057 or since you are in Cali, there are several third parties out there who I can't remember right this second - BUT there are resources who can read the BMS and sort out which specific modules might need replacement, that would get you back on the road a LOT cheaper than those pirates at the SC.

I recommend folks with 2013-15 (out of warranty) vehicles to turn off their wifi. There is no / minimal value you're getting from the OTA updates so at least eliminate one factor that can trigger the BMS_u029.

 

[geordi]

I don’t disagree about turning off the WiFi / forgetting the networks. BUT only b/c of the recent ‘high pitched sounds’ update debacle.

Mine didn’t have that, but I was trying to avoid that update for a while on the off chance that it would develop the problem. But just getting an update won’t create a problem that was not already there. It just means that the problem WAS there, and now you know about it. Or it was a coincidence of the timing.

 

[Paqueti]

hello all, I was reading those 5 pages of battery change and was wondering : when you have a original S85 and you change the battery pack. You take it new they now install a 90 battery pack. Then, you have like a S90 or a S85 restrained (meaning that if you charge up to 100%, in fact you don't charge at the max of the battery).