TESLA MODEL S stopped working... CAR MAY NOT RESTART

[wk057]

The BMS caches cell voltages. You can disconnect the BMBs entirely, and apps like "ScanMyTesla" will still show voltages for cells. You won't see missing data there in most cases.

If you found one sense wire loose, there's almost guaranteed to be others. This happens from moisture, most of the time. If it says a sensor is bad, there's still a sensor bad.

 

[Peter_P]

Thanks again for your fast reply! Although that doesn't sound too promissing...

At least none of the 96 cell voltages are constant and they vary by 0.6-1.5 mV (2-5 bits if I understand correctly) over the ~26 min. measurement, which seems to suggest actual readings to me in this case.

There were no obvious signs of moisture, which I actually was expecting, though the car has been standing still for quite some time.

All voltage readings so far always showed stable voltages over quite some time, with the exception of groups 63 and 64. I also performed some very limited correlation analysis in which groups 63 and 64 clearly jumped out (even though the readings themselves appeared stable). Then it seemed not too big of a surprise when the loose wire turned out to be at the busbar between groups 63 and 64. Unfortunately, we did not check all modules for loose wires, so I can't exclude another loose wire either...

 

[wk057]

If you can send me a raw CAN log at least 3-5 minutes long from the powertrain CAN bus, I might be able to narrow it down more. No guarantees though.

Must be full raw CAN, not output from things like ScanMyTesla

 

[Peter_P]

If you can send me a raw CAN log at least 3-5 minutes long from the powertrain CAN bus, I might be able to narrow it down more. No guarantees though.

Must be full raw CAN, not output from things like ScanMyTesla

Thank you very much for your support Jason! Did not yet manage to get a direct CAN reading (no readings yet via CAN transceiver).

However, even better, I managed to get the car to drive!!

The BMS_f107 showed up today in both active alerts and recent alerts. I noted that the time interval between alerts started increasing. When the recent alert timestap was ~15 min. ago, though the alert still active, I hooked up the Tesla Toolbox and ran the procedures PING-TP_BMS and then PROC_BMS_X_CLEAR-LATCH-BITS. That cleared the BMS_f107 and the car went into drive!

Isolation resistance is 3640 kOhm with contactors open and 1740 kOhm with contactors closed.

I drove the car for ~20 km and did not get any BMS faults (though the coolant level is low which caused me to stop two times). Currently the car is charging (at 3x5A, ~240V, otherwise the charger gets too hot, suppose due to the low coolant level) and tomorrow the coolant will be filled up. So far it looks promissing!

 

[wk057]

Interesting!

Those UDS procedures have absolutely nothing to do with BMS_f107, but running them (and others) from Toolbox does tend to soft reset the BMS.

I suspect there may still be a cell sense wire or two loose. Keep an eye on it.

 

[Peter_P]

Thanks! Somehow I actually do hope your suspicion about the loose wires is not right for our car, for sure I will keep an eye on it.

We took out module 11 from the pack and I checked all wires. Out of the 7 wires, only the wire between cell group 63 and 64 was loose.
The other modules we left in the pack considering if it ain't broke, don't fix it (in hindsight not sure if that was the smartest choice, time will tell...).

To be very precise about what I did:
- Last BMS_f107 alert was today at 11:54:28 (CET)
- Tried to connect to CAN bus with transceiver, but did not work
- Purchased 1h access to Toolbox, which started at 12:21
- Checked isolation resistance and noted it was 3640 kOhm with BMS still in fault state
- Ran procedure PROC_BMS_X_CLEAR-ISOLATION-ALERT-COUNTERS which succeeded; as expected, BMS_f107 was still "active"
- Also ran procedure PROC_BMS_X_CLEAR-CONTACTOR_STRESS which also succeeded, but again as expected, BMS_f107 was still "active"
- Then by the description in Toolbox "This should be run to clear latched alert once the HV battery has been repaired in remanufacturing.", I was hoping that PROC_BMS_X_CLEAR-LATCH-BITS would do something, however it failed (from the UDS trace, after the key was transmitted, there was no reply).
- I ran PING-TP_BMS which succeeded
- Finally, I ran PROC_BMS_X_CLEAR-LATCH-BITS which this time succeeded and then immediately after, the "BMS_f107" alert disappeared as "active alert"
- I put the car into Reverse and it worked! This was at 12:36 (at least that was when I took a picture of it).

Perhaps the time after the last alert also played a role, I don't know how to verify that.

It is now 7 hours later (19:36 in the Netherlands), and the BMS fault has not (yet) come back luckily. The car is only telling me I need to refill the coolant (planned for tomorrow) and that the software needs to be updated (I suppose because of the GTW_w125_dcdcVersionMismatch).

I don't know how the BMS actually determines the sensor fault (missing/erratic data or measure contact resistance with balancers and voltage drop?), but I will keep my fingers crossed that it does not come back and for sure I will keep an eye on the cell voltages and imbalance (still ~9-10 mV)!

 

[rxom]

very interesting for my case ! ....
Jason, i contact you last sunday about a BMB problem that i have on module 8, and you kindly respond to me that errors code will probably disappear when reinstall the HV battery, but was not the case .

I just send you back an email about that...i guess i have my answer here :
I've got all 96 sensor good with only 30mv difference but still BMS f107 and w107 on error:

do you think i must try what Peter did with toolbox 3 ?

Thanks for this post you too anyway !!

 

[Peter_P]

Hope it will work for you too! Let us know.

The coolant for our car was filled up yesterday, 6L added and an air purge was performed. Now our car drives again as before.

Normal charging and Supercharging also works well, during Supercharging the imbalance was ~30-35 mV and now overnight and in rest the imbalance is again ~9-10 mV. So far all looks very promising!

Finally I cleared GTW_w125_dcdcVersionMismatch by running a software reinstall. Only two alerts left in service mode are THC_d0018_activeAero and THC_w0130_radLeftShutrNoFeedback. Perhaps I could run in Toolbox PROC_THC_X_LOUVER-CALIBRATION to get these cleared, but I suppose it is not worth it considering how common these alerts are and the louvers seem to work fine.

 

[wk057]

Jason, i contact you last sunday about a BMB problem that i have on module 8, and you kindly respond to me that errors code will probably disappear when reinstall the HV battery

To clarify, I don't believe anyone at 057 nor myself has said anything quite that definitive on such an issue. We try to be helpful when possible, but no one would have said "error codes will probably disappear when [you] reinstall the HV battery."

In the case of most BMS errors, like stated previously in this thread, they reset themselves after a power cycle IF AND ONLY IF the underlying fault condition is corrected beforehand. If you actually correct a fault, and fire up the battery, if the fault is properly corrected then related errors should disappear (with few exceptions).

Overall, there are very few cases where internal repairs to the battery pack are able to correct an issue reliably and for any long term. Some exceptions, but usually not.

 

[rxom]

maybe i will not exactly quote what you say, but for my error this is quite the answer you give me....

what did you call a "power cycle" exactly ? how can we do that ?
you must understand that when this is the first time we do something, we are not necessary familliar with thing "obvious" for you.

what did you mean by "fire up the battery" exactly ?

thanks,

Rom

 

[Peter_P]

My interpretation of a power cycle is to disconnect the 12V power supply to the BMS (by disconnecting the 12V battery and/or removing the battery from the car) and reconnect.

Overall, there are very few cases where internal repairs to the battery pack are able to correct an issue reliably and for any long term. Some exceptions, but usually not.

What would you consider long term, >1 year? What I am positive about for our car is that the workshop which helped us has more than 10 years of experience with repairing batteries (starting with hybrid cars) and indicated they did not see signs of moisture ingress (I also didn't notice, but I have more experience with solar panels than with car batteries). Our car and battery pack are from 2014 and with serial in the 30k range.

I suspect there may still be a cell sense wire or two loose. Keep an eye on it.

Any suggestion what to focus on? I am now mainly focusing on cell imbalance (in rest or with stable current) and cell temperatures.

 

[rxom]

I've got a problem as i'm unable to connect to toolbox 3 after having paid one day.... i'm very pissed off....
i've got the messaage "cable is not connected".... obvioulsly IT IS connected.... so ... what's going on ???
what am i missing ? here
(i've got the proxy, i manually indicate IP adress, chrome window allow all the thing..... so...what ??)

 

[Peter_P]

That is very frustrating...
You have connected the Tesla Ethernet-FakraHSD cable I assume? In my case it was indeed the steps you describe above. Could it be a physical issue with the cable?

 

[Mike Robinson]

A couple months ago, I returned from a 3-week long trip. My 2018 MS 100D had remained plugged in the entire time I was gone. When I tried to unplug the charging cable, I got no response at all - the car was totally dead, nothing. I could not open the doors, connect with the app, get the displays to light up, nothing. I called Tesla and explained my problem. They remotely connected to the car (so they said) and told me the 12V battery was the issue. Tesla had replaced my 12V battery less than a year previously, so it was still under their warranty. However, I had to get the car to their shop 50 miles away. They arranged for a tow truck, but the cost would be mine ($500). When the tow truck driver arrived, he had to call his company's dispatch team to figure out how to get the car out of my garage and onto his flat bed truck. It took almost 2 hours, but they walked him through the process of unlatching the frunk by going behind both front wheels and pulling a cable. Once he got into the frunk, he attached a jumper battery to the 12V battery on my car, and the car responded. He was then able to disconnect the charger cable and back the car out of the garage and onto his flat bed. He kept the jumper battery connected to the 12V battery on my car all the way to the Tesla shop, allowing the hood to simply rest on the jumper battery. Tesla replaced the 12V battery at no charge, but would not reimburse me for the tow expense. They said the 12V battery they had installed less than a year ago was defective.

 

[brainhouston]

A couple months ago, I returned from a 3-week long trip. My 2018 MS 100D had remained plugged in the entire time I was gone. When I tried to unplug the charging cable, I got no response at all - the car was totally dead, nothing. I could not open the doors, connect with the app, get the displays to light up, nothing. I called Tesla and explained my problem. They remotely connected to the car (so they said) and told me the 12V battery was the issue. Tesla had replaced my 12V battery less than a year previously, so it was still under their warranty. However, I had to get the car to their shop 50 miles away. They arranged for a tow truck, but the cost would be mine ($500). When the tow truck driver arrived, he had to call his company's dispatch team to figure out how to get the car out of my garage and onto his flat bed truck. It took almost 2 hours, but they walked him through the process of unlatching the frunk by going behind both front wheels and pulling a cable. Once he got into the frunk, he attached a jumper battery to the 12V battery on my car, and the car responded. He was then able to disconnect the charger cable and back the car out of the garage and onto his flat bed. He kept the jumper battery connected to the 12V battery on my car all the way to the Tesla shop, allowing the hood to simply rest on the jumper battery. Tesla replaced the 12V battery at no charge, but would not reimburse me for the tow expense. They said the 12V battery they had installed less than a year ago was defective.

Informative but... when the car powered up with external 12v, HV would have turned on DCDC n supplied its own 12v, the car is drivable at this point n doesn't need a tow...
Doesn't make sense to tow unless i'm missing something...

 

[Mike Robinson]

Informative but... when the car powered up with external 12v, HV would have turned on DCDC n supplied its own 12v, the car is drivable at this point n doesn't need a tow...
Doesn't make sense to tow unless i'm missing something...

You clearly know a lot more about this than I do. I was relying on Tesla phone instructions and tow driver. I did not know that once the car is "started", the 12V battery was unnecessary.

 

[brainhouston]

You clearly know a lot more about this than I do. I was relying on Tesla phone instructions and tow driver. I did not know that once the car is "started", the 12V battery was unnecessary.

Shame.. sorry buddy. Tesla failed you
At least now u know

FYI, if u want u can try it urself, start the car then disconnect the 12v.

 

[rxom]

some good news for me : and BIG THANKS to you Peter (i buy my tesla at Endhoven by the way) finally, i discover that i didn't use the right plug.... on our S, it was on the driver side, on the left of the wheel...( at first, i use the plug for the sim card...)
after that, 15 mn later..... that was done ! (using PROC_BMS_X_CLEAR-LATCH-BITS) . i was SO HAPPY to succeed and see it again working after 4 month !!!
I already put 260 km on it without problem ! everything seem to be working perfectly well.

...so now i see that, my conclusion is..... something is not right here and i didn't see the "sustainability tesla thing" if tesla ask 11500 euros for that. ( 60 euros on my side plus mastic and time and a little bit of fees-140 euros for tesla)

Of course you must pay attention ( 350-400 DC, explosion risk, etc) but.... same thing for everything you want to do (like driving, like wood work, etc...)
same things with a thermic ( i remenber the day when on my 80' vette a mouse eat a gas hose ... that almost end on a big fireworks...)
problem is on this so call "modern society" we (gov. and big company) think people are like children and completely dumb. (see what happened with this covid scam).

 

[Peter_P]

Great to hear that you managed to get your car driving again and everything seems to work fine!! Also thanks for sharing/confirming that the procedure also worked for you! (Nice by the way, I live a few km's from Eindhoven.)

In my case the car is also still driving fine without observable issues. In rest, my imbalance also remains stable. After a month or so, I will also check my isolation resistance again.

The price Tesla is asking for a refurbished battery also seems to be too to me high for a minor issue. I do understand that they may do more checks, replacements, apply more safety measures, have more high-end equipment, etc. so a somewhat higher price is acceptable. What is mainly the issue in my opinion is that there is no price differentiation based on the issue and state of the battery.

Safety wise, you definitely need to know what you are doing and take appropriate safety measures. In my case, I have a science background (in physics), experience in working with electricity, and work in the field of solar modules, still I chose to work together with a workshop having experience with battery repairs.

I hope our cars will keep driving without issues for quite some time, fingers crossed!

 

[rxom]

Great to hear that you managed to get your car driving again and everything seems to work fine!! Also thanks for sharing/confirming that the procedure also worked for you! (Nice by the way, I live a few km's from Eindhoven.)

In my case the car is also still driving fine without observable issues. In rest, my imbalance also remains stable. After a month or so, I will also check my isolation resistance again.

The price Tesla is asking for a refurbished battery also seems to be too to me high for a minor issue. I do understand that they may do more checks, replacements, apply more safety measures, have more high-end equipment, etc. so a somewhat higher price is acceptable. What is mainly the issue in my opinion is that there is no price differentiation based on the issue and state of the battery.

Safety wise, you definitely need to know what you are doing and take appropriate safety measures. In my case, I have a science background (in physics), experience in working with electricity, and work in the field of solar modules, still I chose to work together with a workshop having experience with battery repairs.

I hope our cars will keep driving without issues for quite some time, fingers crossed!

100% agree about the price differenciation thing: in france we have only one choice : refurbished batteries with excessive price (11500 euros). i was ready to pay a little more for a new pack with 500 km and tesla service did a quotation for me (15500 euros if i remenber well) but 10 minutes later, they told me that tesla france didn't allow them to do this.... so shame...(in US u can have a new pack with 290 miles on an old S) this could be great as this is like having a new car in my opinon).