Car died. BMS errors f123, w123, w073, w035, w142, w158

[goodbadboys9]

All of this ^

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Based on everything noted, the pack is 99% likely water damaged and at this point unrecoverable. Resetting f123 will do nothing to fix this, either. (I also posted how to do this in another thread somewhere, btw... don't pay anyone to do this.)



This is almost certainly the result of water that has settled physically moving while you drive. Stop trying to drive it. If you're hitting 20 kOhm of iso (and keep in mind that's an average over a multi-second measurement), that's almost a direct short of HV to chassis. Just stop trying to use this car. That's actually well into unsafe-to-touch territory. I wouldn't even let my crew disassemble a pack with that low isolation resistance since it makes the unsafe-to-touch areas effectively the entire chassis. I'd maybe do it myself, very carefully because I've done hundreds of packs, in full HV protective gear if absolutely needed, but most likely would just dispose of it instead since in our experience there's not much to be recovered from such packs, if anything.

Sorry can't be of more help here, but a pack replacement is going to be your only option. Water damage, even if "dried out" leaves lasting damage to the cells... especially since you've been trying to utilize it despite the issue. Even if you manage to clear the isolation problem both physically and electronically, the pack won't last very long, if at all.

Tesla's refurbished replacement is your best option for water damaged packs, since they don't care about the condition of the core pack as long as there is a core pack. So I'd suggest going that route. Otherwise I'd just scrap the car and move on.

057 won't be able to give you much of anything for your core pack if water damaged, and I'd guess Recell would be in roughly the same boat there with their replacement offerings.

It's worth emphasizing: This pack is NOT safe to dismantle, and I would NOT suggest doing so.

I thought you said BMS F123 can't be reset.

Can we reset it & how can we do it for testing purposes?

 

[wk057]

I thought you said BMS F123 can't be reset.

Can we reset it & how can we do it for testing purposes?

Whoops, you're right. Mixing up my errors. BMS_f027 is the resettable one.

But the fact that you still want to just try to reset things despite everything noted... I think I'll be done with this thread.

Best of luck!

 

[goodbadboys9]

Whoops, you're right. Mixing up my errors. BMS_f027 is the resettable one.

But the fact that you still want to just try to reset things despite everything noted... I think I'll be done with this thread.

Best of luck!

Sorry.I was just genuinely curious & I am not the OP.

Please help the member if you can & you have great knowledge on these errors & unparalleled

 

[wk057]

Sorry.I was just genuinely curious & I am not the OP.Please help the member if you can

Good point.

I need to stop speed reading through threads. lol

 

[brainhouston]

Based on everything noted, the pack is 99% likely water damaged and at this point unrecoverable. Resetting f123 will do nothing to fix this, either. (I also posted how to do this in another thread somewhere, btw... don't pay anyone to do this. EDIT: Correction, BMS_f123 is not the resettable isolation error, that's BMS_f027... BMS_f123 is NOT resettable, so still don't pay anyone to do this haha)

wk i appreciate all ur input n knowledge but I CLEARLY said in above post that f123 did reset. I'm not sure why ur saying it can't be...
i understand that maybe it can't be reset if isolation is still low but in my case it was normal at that time, so i did it for testing purposes obviously, not trying to drive the car...
I did saw ur other post about resetting BMS errors but it didn't specify f123 n i didn't have time to research n buy CAN shield so yes i did pay someone who's smarter than me

FYI, there's also a youtube video of EV clinic fixing water damaged battery n resetting f123 error as well.

I'll get to the bottom of this, luckily for me i know what i'm doing lol

Also, i understand 400v risks but in reality even if one of the buses is welded to ground (which is not cause water is not a metal) u still need a path for current to flow to the other side... so chances of being electrocuted are low. And if water would touch both buses then battery would discharge or melt itself...
I've already touched the bottom of pack n i'm still alive. Just my 2c.

i'll keep this thread updated. if i disappear then i guess battery won jk jk

 

[Recell]

Tesla's refurbished replacement is your best option for water damaged packs, since they don't care about the condition of the core pack as long as there is a core pack. So I'd suggest going that route.

057 won't be able to give you much of anything for your core pack if water damaged, and I'd guess Recell would be in roughly the same boat there with their replacement offerings.

precisely. ^

the absolute last thing any of us want to tell a customer is 'sorry, we don't have solution for you...'

unfortunately, when it comes to an internal isolation fault, there's little we can do - there's just no way to credibly certify a core once there's been water damage and we're straight up about that with all our customers. about the only time we'll bring one in would be for in-house testing and R&D.

 

[wk057]

The only way to "reset" f123 is to correct the issue, then it resets itself. Might trigger f027 which will need resetting, though.

Here's how the isolation issue is hazardous. You're working on disassembling the pack. Now to make a complete circuit, it's just touching the ground or pack chassis while touching anything else live. Instead of having to touch two live parts to die, you just lean the wrong way with your leg against the chassis or something and you're having a bad time.

Honestly, I used to be more cavalier with it. Figure I'll just be careful, never touch the wrong things, etc. Except I've personally been bitten by a pack with 400kOhm of internal isolation by being a bit too careless years ago. Not going to make that mistake again... let alone at 20kOhm! At least at 400kOhm I got a <1mA tazer-like nibble and could yoink myself away (hurting myself in the process...er). At 20kOhm you're looking at heart-stopping currents... so, nope.

And honestly, everything I've seen on YouTube about Tesla battery repair is 100% BS. Either complete non-fixes, or very temporary bandaids at best.

I understand trying to save a buck, I really do. But internal isolation failure is where you cut your losses and move on when it comes to these packs.

 

[Recell]

Indeed. we were getting ready to disassemble a pack a few months back with all the usual precautions, etc. then looking at the onboarding log. wait. stop. this was a wet pack with an isolation fault right? nope. nope. none of those precautions apply now. we need to stop immediately, and shut this pack down.

related/unrelated:
the old packs that Tesla made for the FourTwo Smart Car and the RAV 4 had the fuse right in the middle of the series connected modules so that as soon as the fuse blew (or was removed), the voltage potential of the pack was immediately cut in half. a welcome safety feature, since 200V sure beats 400V... but have always been surprised that Tesla didn't use a similar module topology on the Model S packs. (note: some mistakenly assume that the main fuse on the Model S also cuts the pack in half since it's located between the #7 and #8 module, when in fact #7 and #8 are actually the 14th and 15th module in the series)

 

[brainhouston]

... but have always been surprised that Tesla didn't use a similar module topology on the Model S packs. (note: some mistakenly assume that the main fuse on the Model S also cuts the pack in half since it's located between the #7 and #8 module, when in fact #7 and #8 are actually the 14th and 15th module in the series)

Does this apply to newer packs that have pyro fuse on the bottom?

 

[Recell]

nope. the bus topology is the same on the newer packs as well, the main fuse is just inverted with access from the bottom vs. the top.

folks often assume, incorrectly, that because of the network order of the modules 1-7 up the one side, 8 and 9 in the penthouse, and then 10-16 back down the other side, that the modules are also in series up one side of the pack and then back down the other. when in fact, the series string actually zig-zags back and forth across the pack, building potential as it goes up the length of the pack until finally 8 and 9 are the last in the series string. that's true of all the Model S packs, at least 2012-2020.

the series order in the Model S packs is actually: (+)->9->8->7->10->6->11->5->12->4->13->3->14->2->15->1->16->(-)

will try to find a diagram illustrating the layout.

 

[brainhouston]

Took off the pyro cover n the fuse.
While there's no signs of water/moisture here, its measuring 140v to ground on copper bus n 25v on silver bus..
Definitely something shorted inside... this is gonna be fun

 

[Recell]

actually @brainhouston, not so quick. that voltage to ground is always there - that’s how the BMS measures the actual isolation resistance.

BUT it does NOT mean that your pack is safe either.

don’t think @wk057 and the team here at @Recell can encourage you enough NOT to do this.

 

[wk057]

Yeah, the BMS uses a clever setup of mosfets, opamps, and ADCs to place different known resistances across the HV terminals and chassis (in the megaohm range) in order to measure isolation resistance changes, so there's always some voltage there, but the max current is limited to almost nothing, normally.

 

[Recell]

@brainhouston, the key in @wk057 post above is 'NORMALLY'

think of it akin to an electric fence - high voltage, 300V+ dumped very quickly when shorted to ground, enough to give you a jolt.

again, please do NOT test that out.

 

[brainhouston]

Well, I found this:

Left side, first plug, right where the scratches on the battery are from accident.
Lesson learned, if the umbrella cover is dented, remove n inspect..
I'm a bit surprised that such a small hole on the bottom could cause a lot of water to get inside, i never drove thru any deep puddles

Top of the battery looks immaculate, no signs of water intrusion...

 

[Recell]

@brainhouston, it doesn’t take much. Operational spec is around 200-400 kΩ and the isolation needs to be north of 900+ kΩ immediately after the contactors are closed. (will go look up the exact tolerances in the service guide, it’s somewhere between 900-1500 kΩ when the contactors are first closed, but that’s the rough order of magnitude).

With up to 400V of potential sitting behind it, the isolation tolerances are very strict - measured in Mega Ω - and for good reason. It doesn’t take much to trip them and take the pack offline. (we often joke that the BMS is a lot like Gordon Ramsey - “Shut It Down!!” )

fwiw: we had a pack in just before the holidays with this EXACT kind of damage. bashed in rail from a hard drop onto a curb, etc., subsequently cracked the umbrella, in PRECISELY the same way you have pictured.

resulting moisture intrusion was visible inside one of the module galleys, but it wasn’t causing an isolation issue (at least not by the time the pack came in). Instead, it was causing all sorts of havoc with one of the BMBs and the voltage sensors on one of the modules - this is what @wk057 was likely referring to previously about pack reliability - even if you can dry the pack out and resolve the source of an isolation issue, once the seal has been broken…

either way, the pack went into our in-house testing inventory since there’s no way to we could certify a pack after that kind of visible damage and moisture intrusion.

 

[brainhouston]

@brainhouston, it doesn’t take much. Operational spec is around 200-400 kΩ and the isolation needs to be north of 900+ kΩ immediately after the contactors are closed. (will go look up the exact tolerances in the service guide, it’s somewhere between 900-1500 kΩ when the contactors are first closed, but that’s the rough order of magnitude).

With up to 400V of potential sitting behind it, the isolation tolerances are very strict - measured in Mega Ω - and for good reason. It doesn’t take much to trip them and take the pack offline. (we often joke that the BMS is a lot like Gordon Ramsey - “Shut It Down!!” )

fwiw: we had a pack in just before the holidays with this EXACT kind of damage. bashed in rail from a hard drop onto a curb, etc., subsequently cracked the umbrella, in PRECISELY the same way you have pictured.

resulting moisture intrusion was visible inside one of the module galleys, but it wasn’t causing an isolation issue (at least not by the time the pack came in). Instead, it was causing all sorts of havoc with one of the BMBs and the voltage sensors on one of the modules - this is what @wk057 was likely referring to previously about pack reliability -even if you can dry the pack out and resolve the source of an isolation issue, once the seal has been broken…

either way, the pack went into our in-house testing inventory since there’s no way to we could certify a pack after that kind of visible damage and moisture intrusion.

Thank you for your input, much appreciated.
At least i'm glad to hear i'm not the only one with this issue n it pretty much confirms the cause.
I'm genuinely curious tho, where does water caused low isolation... is it just touching the bottom of any cell or some bus bar?..
Maybe on newer pack BMBs are better protected?.. cause i had zero issues with bricks, all voltages showed as good n balanced.

If the link i posted above to be trusted, it seems to match what ur saying

 

[brainhouston]

@Recell you're correct, when i unplugged BMS HV, my voltages at pyro are now 2.5v n 50v... still not sure why 50v is there tho...

FYI, from my quick measurements, it seems pyro is between 14th n 15th module (guess this was done to streamline 14/16 module packs)
I get 335/50v between pyro n contactors but my full pack was at 385v when i shut it down.

One down, 2 more to go...

Anyone know what kind of silicone is used to seal the covers? just thinking ahead for what to use when i get to cover it back up...

 

[brainhouston]

2 down, one more to go ...

no puddles but some moisture on left side where broken plug is

 

[brainhouston]

and the pack is open... nobody got zapped or hurt
removing big main cover is next to impossible without mangling it too much, did my best but...

water traces in 5 circled modules with most wet ones are 1st two (arrows), its expected since they are closer to damaged plug.
not sure how the pack frame is built but seems water can penetrate between sections
no puddles of water, just enough there under emf bottom shields (or whatever they're called) n a bit in plugs
still not sure how its shorting since modules are suspended n not touching the bottom n there's not enough standing water to touch bottom of the module
maybe bus bar down the center runs low to the bottom? anyone know??

and the culprit...

one thing i've noticed is pack bottom is designed that plugs/umbrella valves are actually few mm higher than the bottom of each section.
u can see it from the outside front of the pack... can't use these vents to fully drain the pack from water...

Gonna work on drying it n testing isolation. Still debating whether to pull the modules or not... All modules/cells looks good that i can see. Voltages similar on all, 23.8V...
Pyro bus to ground is at 16V rn so it looks like its drying n isolation goes away, was 50v after disconnecting BMS HV.
If my deduction is correct it seems 1st or 2nd modules are shorting to ground since i get ~3v at one of those terminals to ground (not fully sure about series bus layout yet...), other points get 25/50/etc depending where u measure...

and some measurements for plug/o-ring if ur curious.