2012 Model S Battery issues and alerts

[Testurs]

Making this thread as part 2 to the saga of getting my model S to work. The drive unit is properly synced (Model S Rooted v11.0 2022.8.10.5 drive unit replacement problems), however now there are now battery issues. I was told there were no battery issues before the drive unit died by the previous owner (about 2 months ago), however I cannot verify this fact.

This current battery pack was put into the car around April of 2022 by Electrified Garage (I was told it was a "newer battery pack" but was never given the exact specs. the sticker by the passenger front well is pretty poorly degraded too).

Before fully fixing the drive unit, the code "BMS_w_107_SW_Cell_Voltage_Sensor" started to appear (from my records this code started to appear sometime in the last 3-4 weeks, and the car has not moved or driven at any point. It was towed and jacked up several times for replacing the drive). Now that the drive unit is fixed and synced, there are numerous BMS codes (see picture). I have also attached a picture of the current BMB Voltages. I have not checked for isolation issues, but the error messages don't suggest it. BMS_w155_SW_BMB_Vref_leaky and BMS_f097_HW_BMB_Under_Voltage and BMS_f098_HW_BMB_Over_Voltage also intermittently appear. I believe all the other codes are present because of the BMS problems.

From what I can tell, module 10 has a difference in voltage of .087v, and I am wondering if module 10 is the cause of all these current problems. The error messages seem to point to it, but I wanted to see if anyone had more information. Looks like the pack will need to be pulled, which I will do if needed. How practical will a module replacement be if I can CAC match and find one that is about the same age/part number? I know I will be told to just get a new/used pack by some on this forum, but that is not an option for me. I would rather part the vehicle out instead of spending 5-15k on a pack, simply because the car is not worth that much. Or, is there something else that I am missing, like a connector or wire?


The BMS Codes are:
BMS_f071_SW_SM_TransCon_Not_Met

BMS_ w164_SW_Brick_SOC_Imbalance

BMS_ w166_SW_AhToBeCharged_Imbal

BMS_4008_limpMode

BMS_W129 _SW_BMB_VSH_Connector

BMS_w107_SW_Cell_Voltage_Sensor

 

[brainhouston]

I was told there were no battery issues before the drive unit died by the previous owner (about 2 months ago), however I cannot verify this fact.

yeap, never trust the seller

This current battery pack was put into the car around April of 2022 by Electrified Garage (I was told it was a "newer battery pack" but was never given the exact specs. the sticker by the passenger front well is pretty poorly degraded too).

i doubt its newer and you'll verify when u open it
f107 is a common error for older packs when sense fires fall off (its just a single standard wire) later they switched to ribbon cable with redundancy.
good news is ur cells themselves probably fine
bad news u have to open the pack n re-attach the sense wire (not easy cause u can't solder) AND check ALL of them (cause another one might fall off later)

How practical will a module replacement be if I can CAC match and find one that is about the same age/part number?

not very practical cause most sellers don't check the CAC...
with missmatched module you'll end up with another error soon

I know I will be told to just get a new/used pack by some on this forum, but that is not an option for me. I would rather part the vehicle out instead of spending 5-15k on a pack, simply because the car is not worth that much. Or, is there something else that I am missing, like a connector or wire?

its a good option cause u can still sell ur old modules n make money back
there was one guy on fb 029 group that did that n basically netted profit
but i understand the hassle

if ur set on parting out, u can still make a profit (hopefully) or use it to fix another one
i'd also get late 2016 or later car, those had a lot of issues fixed

 

[Testurs]

I will send pictures of the battery once I remove it. Interested to see what is in there too. It likely is an older battery, but let's see once I get it off.

That is an interesting take. Are you thinking that all of these codes are being caused by sense wire(s) being loose? I was concerned about the .087v difference, is that not a significant problem (I did read somewhere only over .1v indicates an issue, but that information was not from an authoritative source)? I also have a screenshot of the BMBs on May 5, and the voltages were a bit different (attached). That upper left voltage on module 10 appears to be losing charge faster than all other areas, but I am not convinced this is a major problem (yet).


I didn't think it would be practical to sell a defective battery, but that makes sense. How much do these go for when there is a known issue, such as what I am experiencing?

 

[Testurs]

I did the subtractions, and it does look like the upper right reading on module 10 is different from the others (.014v, whereas the other highest is .009v lost from May 5 to May 25). I am still not convinced this is a significant enough problem to cause all these codes, but it makes me think a select few cells (or even 1 cell) are degrading more on module 10.

 

[brainhouston]

That is an interesting take. Are you thinking that all of these codes are being caused by sense wire(s) being loose? I was concerned about the .087v difference, is that not a significant problem (I did read somewhere only over .1v indicates an issue, but that information was not from an authoritative source)?

yes most definitely
also if u notice on modules 7/10, one brick is higher the other is lower by about same amount, cause sense wires are shared, except end ones i think
Edit: same with latest screenshot (this is very common with f107)

once u open the pack, u can confirm all cell voltages with multimeter
when sense wire gets loose, before completely falling off, it has higher resistance value so its just not measuring correct voltages n u can't trust the numbers
i wouldn't worry about discharge differences at this point

I didn't think it would be practical to sell a defective battery, but that makes sense. How much do these go for when there is a known issue, such as what I am experiencing?

in this case its not defective per se, just lost a sense wire connection
u won't get much for selling complete pack but selling just the modules (~$500/ea give or take) is the way to go, plus other internals...
many use them for solar or EV conversions

 

[Testurs]

That would be much better than having to go through modules or worse!

Also, as a completely crude but legitimate test (I am used to working on ICE cars), I grabbed the tesla with both hands and shook the car at various angles, and it looks like the error codes changed! Maybe that wire is slightly moving around in there.

I will take off the battery now and get back to you (brainhouston) and this thread in general with more pics/numbers, so that my next response is more meaningful.

 

[NV Ray]

In addition to @brainhouston contributions, this Facebook Group is the go to source comprised of previous effected owners and 3rd party professionals. BMS_u029/18/a066

Further these FAQs will be of assistance www.superchargertravel.com

@islandbayy FYI

 

[brainhouston]

Also, as a completely crude but legitimate test (I am used to working on ICE cars), I grabbed the tesla with both hands and shook the car at various angles, and it looks like the error codes changed! Maybe that wire is slightly moving around in there.

not seeing diff codes, just moving active<>inactive, which is normal depending on state of the car
don't think that test will shake a sense wire unless ur a hulk maybe

 

[islandbayy]

Making this thread as part 2 to the saga of getting my model S to work. The drive unit is properly synced (Model S Rooted v11.0 2022.8.10.5 drive unit replacement problems), however now there are now battery issues. I was told there were no battery issues before the drive unit died by the previous owner (about 2 months ago), however I cannot verify this fact.

This current battery pack was put into the car around April of 2022 by Electrified Garage (I was told it was a "newer battery pack" but was never given the exact specs. the sticker by the passenger front well is pretty poorly degraded too).

Before fully fixing the drive unit, the code "BMS_w_107_SW_Cell_Voltage_Sensor" started to appear (from my records this code started to appear sometime in the last 3-4 weeks, and the car has not moved or driven at any point. It was towed and jacked up several times for replacing the drive). Now that the drive unit is fixed and synced, there are numerous BMS codes (see picture). I have also attached a picture of the current BMB Voltages. I have not checked for isolation issues, but the error messages don't suggest it. BMS_w155_SW_BMB_Vref_leaky and BMS_f097_HW_BMB_Under_Voltage and BMS_f098_HW_BMB_Over_Voltage also intermittently appear. I believe all the other codes are present because of the BMS problems.

From what I can tell, module 10 has a difference in voltage of .087v, and I am wondering if module 10 is the cause of all these current problems. The error messages seem to point to it, but I wanted to see if anyone had more information. Looks like the pack will need to be pulled, which I will do if needed. How practical will a module replacement be if I can CAC match and find one that is about the same age/part number? I know I will be told to just get a new/used pack by some on this forum, but that is not an option for me. I would rather part the vehicle out instead of spending 5-15k on a pack, simply because the car is not worth that much. Or, is there something else that I am missing, like a connector or wire?


The BMS Codes are:
BMS_f071_SW_SM_TransCon_Not_Met

BMS_ w164_SW_Brick_SOC_Imbalance

BMS_ w166_SW_AhToBeCharged_Imbal

BMS_4008_limpMode

BMS_W129 _SW_BMB_VSH_Connector

BMS_w107_SW_Cell_Voltage_Sensor

Ray's got it covered. Take a look at the FAQ at www.SuperchargerTravel.com and join the group. We have all the Pro's that can help get you back up and running!

 

[Testurs]

Got the battery out last night. Whether the hulk test worked or not, I definitely had to pull hard to get the battery out when it was on wheels because I forgot to pull out the rubber mat! I do not have any special equipment or lifts, this is doable with basic equipment.

I got the penthouse off and there is water. It is not coolant, I think it is accumulated condensate. It actually does not look that bad, hopefully it is not detrimental and can be saved. I did not see any codes to indicate water ingress, and the cells look relatively untouched (there is a bit of condensate on the inside of the plastic shell).

It is also the older type module, that distinct wire is there, so far brainhouston is on the money!. Is there a wire on the bottom of the module too, or just the top? Interesting that there is a pyro fuse instead of a sand fuse, I guess it is a refurbished pack from electrified garage (they took no shame in branding their logo on the fuse cover).

I will pull off the rest of the cover too, and pump out the coolant.

Thanks for the forum/fb suggestions, I will take a look at those and see what I can contribute/gather.

 

[Testurs]

A few more pictures:

 

[NV Ray]

@mr_hyde FYI

 

[yutian]

The pressure difference of 0.087V is very normal, it will not affect anything. You can check the battery package wiring. If the car has had an accident, it is possible to loosen the battery collection line. In addition, the voltage displayed on the MCU screen may not be accurate. You need to unpack the battery pack and measure it.

 

[brainhouston]

Got the battery out last night. Whether the hulk test worked or not, I definitely had to pull hard to get the battery out when it was on wheels because I forgot to pull out the rubber mat! I do not have any special equipment or lifts, this is doable with basic equipment.

I got the penthouse off and there is water. It is not coolant, I think it is accumulated condensate. It actually does not look that bad, hopefully it is not detrimental and can be saved. I did not see any codes to indicate water ingress, and the cells look relatively untouched (there is a bit of condensate on the inside of the plastic shell).

It is also the older type module, that distinct wire is there, so far brainhouston is on the money!. Is there a wire on the bottom of the module too, or just the top? Interesting that there is a pyro fuse instead of a sand fuse, I guess it is a refurbished pack from electrified garage (they took no shame in branding their logo on the fuse cover).

I will pull off the rest of the cover too, and pump out the coolant.

Thanks for the forum/fb suggestions, I will take a look at those and see what I can contribute/gather.

nice work!
most likely water got in thru fuse cover, was it rusted?
ur pack was definitely on its way to f123 error if f107 didn't happen...
there's a theory that moisture weakens sonic welds
yes there're sense wires on both sides

Tesla switched to Hybrid (with internal battery) fuse before they switched to newer pack style (with fuse on the bottom)
Now they switching everyone to Current powered, u should too while u at it, fairly cheap on ebay (just need toolbox to change the type)

 

[Testurs]

It doesn't look like it was the fuse cover, it was dry in there. EG also put so much gasket around it, it took a long time to even clear the material. There was heavy condensation on all the aluminum coolant pipes in the pent house, there was also water around the quick release coolant ports. I am thinking it was a combination of condensation and imperfect seal around the coolant port, but the fact that there was no coolant inside is strange. It was all just pure water.

I am assuming this pack is worth saving, since the rest of the modules looked dry (one of the modules had some mild rusting/pitting on some cells (I am attaching a picture, but it is hard to see). I guess I have to take off each pack and check the sense wires, because the top on all of them were tightly in place (I loosened the plastic covers to check). By the way, how are these modules counted? There are two in the penthouse, so which one is module 10?

Any advantage to switching the fuse? I likely won't make the switch since the car is still on v11 software and I was told it won't update until all codes are resolved. My version is too old for toolbox 3 and I doubt toolbox 2.1 offline could make the update. I will keep it in mind though, especially if I can get this thing working again.

 

[Testurs]

Found the positions:

Will pull 7 and 10 to see if the bottom wires are loose, since that is theorized to be the problem

 

[brainhouston]

It doesn't look like it was the fuse cover, it was dry in there. EG also put so much gasket around it, it took a long time to even clear the material. There was heavy condensation on all the aluminum coolant pipes in the pent house, there was also water around the quick release coolant ports. I am thinking it was a combination of condensation and imperfect seal around the coolant port, but the fact that there was no coolant inside is strange. It was all just pure water.

I am assuming this pack is worth saving, since the rest of the modules looked dry (one of the modules had some mild rusting/pitting on some cells (I am attaching a picture, but it is hard to see). I guess I have to take off each pack and check the sense wires, because the top on all of them were tightly in place (I loosened the plastic covers to check). By the way, how are these modules counted? There are two in the penthouse, so which one is module 10?

Any advantage to switching the fuse? I likely won't make the switch since the car is still on v11 software and I was told it won't update until all codes are resolved. My version is too old for toolbox 3 and I doubt toolbox 2.1 offline could make the update. I will keep it in mind though, especially if I can get this thing working again.

i think aluminum just captures moisture better kinda like glass in the bathroom
fuse cover from factory has lots of black tarr so maybe normal
yes i think its worth saving, dry n re-check all sense wires n BMBs
some pitting on cells is no issue, i had it on my pack n it ran for 10k+ miles already with no issues
hybrid fuse has internal li-ion battery that will eventually deplete n pop the fuse, since its on the top it makes sense to switch even if u don't get to changing setting (u'll just have error code pop up later, its time based), also with MCU1, smart ppl like LayZ can remotely change that setting for u

keep in mind that if all sense wires check out, u might have issues with BMB boards
check out this thread:

2014 P85d High Voltage Failure

Unfortunately, I ended up with a HV battery failure last night – 2014 P85D. There were buckets of errors on the screen mostly related to a dead 12v which I hoped was the issue so I replace it. When the car came back on, the errors persisted. ScanMyTesla shows Cell 46 down over a volt and Cell 47...

teslamotorsclub.com

 

[Testurs]

I believe I found the the problem (it might be more accurate to say "a" problem, depending on the condition of the rest of the modules). brainhouston was exactly right, very impressive (you have pointed out correct solutions for 2/2 significant problems I have been having with this car, thank you!)- The bottom side of module 10 has some condensation/mild rust, and sure enough the orange sense wire is loose, likely because of the water. I do not know which brick the orange wire goes to, but I am willing to bet it is the one of the ones giving the off reading on the BMB pic.

The next challenge is how to reattach these wires, and more importantly how to engineer a viable long-term solution to this problem. It looks like glue was used to hold the wire in place ... what about mild sanding and applying a tiny amount of JB weld or liquid gasket? Liquid gasket especially would be good for vibrations/water, but it would have to be done carefully so that the wire is still making good contact with the metal. I have another idea in mind, but it is more dangerous and I want to think about it before posting. Open to any solutions here.

 

[mr_hyde]

I'm not sure about the best way to reattach the wire, but I've heard some people use a ring terminal soldered to the wire and a screw or rivet. Just be very careful where the back side of the screw or rivet hole goes!

My best advice since you have gone this far is to check, clean and recoat EVERYTHING. Get some 100% alcohol an a bunch of cotton swabs and a bottle of conformal coating. Clean everything. Poke every connection with a pick - don't trust a single one. If it is securely attached and with no sign of corrosion, recoat it to keep moisture out in the future. Check every BMB for corrosion. Use a jeweler's visor. Pay special attention to C26 and C27. I don't know about your year, but in 2014/2015 packs, they corrode because the lower cover rubs on them where it overlaps with the top cover. Remove EVERY module for this and take day, not hours to go over everything methodically. Your time is 'free' as a DIYer but the time it takes to drop and open the pack is significant so do it right the first time.

Two last bits of advice on pressure testing. Test the coolant loop before you flood the system. I nicked one of the tubes opening the lid and it cost me 2 more weeks dealing with it. Once you are happy with everything and seal the pack, pressure test the pack itself. It is difficult to get it to hold pressure with all of the venting points so use a spray bottle of warm water and dish soap and look for bubbles. This is the step the last guys probably skipped and it is a stupid corner to cut.

Great work getting this far! There is no reason this pack won't go back in and be as good as new in terms of connections, seal and corrosion. Someday, a cell will die and you will need to deal with that but for now, be happy you got the 'good' kind of failure with 16 viable modules.

 

[brainhouston]

I believe I found the the problem (it might be more accurate to say "a" problem, depending on the condition of the rest of the modules). brainhouston was exactly right, very impressive (you have pointed out correct solutions for 2/2 significant problems I have been having with this car, thank you!)- The bottom side of module 10 has some condensation/mild rust, and sure enough the orange sense wire is loose, likely because of the water. I do not know which brick the orange wire goes to, but I am willing to bet it is the one of the ones giving the off reading on the BMB pic.

The next challenge is how to reattach these wires, and more importantly how to engineer a viable long-term solution to this problem. It looks like glue was used to hold the wire in place ... what about mild sanding and applying a tiny amount of JB weld or liquid gasket? Liquid gasket especially would be good for vibrations/water, but it would have to be done carefully so that the wire is still making good contact with the metal. I have another idea in mind, but it is more dangerous and I want to think about it before posting. Open to any solutions here.

You're welcome!
It wasn't glue, Tesla using sonic welds (unless there's evidence that pack was opened before)
I think there is portable sonic welder tool but pretty pricey
Best bet like MrHyde said is to rivet it
JB or similar won't make good connection, don't risk it