Advice: BMS_w035 - battery coolant heater? Causing other alert codes too.

[wk057]

@wk057 what is the best method to reach out to you? I want to make sure I have multiple options for repair once I hear back from SC. How does it normally work with clients whom are far away from you in regards to logistics?

Best way is usually the contact page on 057tech.com, that way if I don't personally catch it then you're still not lost in the sauce.

We usually would help arrange vehicle transport from you to us to get the car here for diagnostics/troubleshooting, figure out what's up, quote that, and go from there.

I'd bet in your case it's either the pack heater or drive unit, but hard to say without more data.

 

[dwbv]

@wk057 thank you, I will surely reach out when appropriate.

On a side note, could air in the coolant lines mess up the pack heater and then throw an error? I noticed today when I got home that there were some swishing sounds from one of the coolant lines while the pumps were running. When I tried to crimp the line a bit with my bare hands, the sound would go away. It's possible that I'm just cutting off the circulation but I would think that coolant flowing should be almost silent? It may be nothing, just drawing straws here.

 

[wk057]

Air in the lines could definitely damage the pack heater and eventually cause an isolation issue. There shouldn't be any air unless the coolant tank is low, though... and if the coolant tank is low then you've lost coolant somewhere... which is another problem.

 

[islandbayy]

@wk057 what is the best method to reach out to you? I want to make sure I have multiple options for repair once I hear back from SC. How does it normally work with clients whom are far away from you in regards to logistics?

He's at www.057Tech.com and Excellent at what he does
What part of Wisconsin are you in though? You didn't get your car from a small little dealership in the Madison Metro area did you?

 

[dwbv]

Air in the lines could definitely damage the pack heater and eventually cause an isolation issue. There shouldn't be any air unless the coolant tank is low, though... and if the coolant tank is low then you've lost coolant somewhere... which is another problem.

Coolant is fine. The car's on the charger when I'm not out test driving in limp mode and I've noticed that the pump motors are running. My guess is that the car is trying to keep itself warm? I'll keep an eye on the level however I'm not suspecting any issues here. I've not touched the coolant since it's been with me at my home.

He's at www.057Tech.com and Excellent at what he does
What part of Wisconsin are you in though? You didn't get your car from a small little dealership in the Madison Metro area did you?

I'm in central WI and my P85D came from out of state.

 

[islandbayy]

Coolant is fine. The car's on the charger when I'm not out test driving in limp mode and I've noticed that the pump motors are running. My guess is that the car is trying to keep itself warm? I'll keep an eye on the level however I'm not suspecting any issues here. I've not touched the coolant since it's been with me at my home.

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I'm in central WI and my P85D came from out of state.

Ok, there is a dealer by madison trying to pass off a 2013 Model S 60 as a performance model with autopilot and lots of features it doesnt have, that came from auction.

 

[dwbv]

Wow, did some internet searching and came across this: Ski Trip in Tesla Model X Gone Wrong!

It's like deja vu with the exact same behavior and errors but I still have cabin heat and some coolant heat. I suppose it's only a matter of time before my heat goes. Good thing is that it is starting to get warmer where home is.

The fix was the battery heater so hopefully mine is the same. Rather ~$1k on a heater than ~$6k on a LDU.

 

[wk057]

If you have a CAN tool you can try the reset procedure for that remaining isolation error (I posted it somewhere here, not sure where) if others are no longer appearing, but that's not a fix for the underlying problem. Just a diagnostic tool so you can narrow it down without a megohm meter.

 

[dwbv]

If you have a CAN tool you can try the reset procedure for that remaining isolation error (I posted it somewhere here, not sure where) if others are no longer appearing, but that's not a fix for the underlying problem. Just a diagnostic tool so you can narrow it down without a megohm meter.

Is that different than the OBD hardware to use the ScanMyTesla app? If so, is that something I can buy to just have it around for situations like this? Could you provide a link?

I've been driving the car here and there hoping that it will "restore itself on the next drive".

Surprisingly though, the BMS_w035 has not popped up again since.

 

[wk057]

Is that different than the OBD hardware to use the ScanMyTesla app? If so, is that something I can buy to just have it around for situations like this? Could you provide a link?

I've been driving the car here and there hoping that it will "restore itself on the next drive".

Surprisingly though, the BMW_w035 has not popped up again since.

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

It’s not due to recent software updates. I got the same errors last year and they’re too generic to always map to a specific issue. Remote diags pointed to failing battery coolant heater as well so it was replaced under warranty. If you’re up for a DIY replacement, the HV piece shouldn’t scare...

teslamotorsclub.com

You'll need to be able to send those CAN messages in sequence within a second or so. The hardware used for SMT should technically be capable of this, but unsure. You'd have to investigate. The official tool used by Tesla is the PCAN adapter, and you can use PCAN-View to send the messages.

 

[tesluv108]

2015 P85D, 15k miles, warranty died on 3/31/23, bought it 3 weeks ago, in my possession for only 1 week, driven less than 20 miles.

Well, I suppose this is part of owning a Tesla. One week of physical ownership and here we go. The first 6 miles of driving was fine. Took it out this morning for another drive and on the way back home about a mile from home, I got the BMS_w035 alert. No hard driving and no higher than 65mph max. It drove fine all the way back home. Parked it and plugged in the charger. Shortly thereafter, checking up on the car also showed BMS_u016, then BMS_w172 showed up followed by BMS_u008.

Looked up many threads on this issue on here and it seems to be the battery coolant heater? It's been cold in my garage but nowhere near the sub-zero F degrees. Supposedly the 12v battery? I tore the front apart and looked at the battery. The negative terminal was a bit loose so I tightened that up. Powered down the car and powered it back up after 2 minutes as recommended. Same alerts remain.

I did take the car out and was able to drive it without issue albeit no regen and only under-100kW. Everything else seems to work just fine.

Is there anything I can do? I'm tempted to pull the 12v and the fireman's loop for a hard reboot since I've got the front wide open but I'm thinking that won't do anything. I'm 2.5 hours away from the closest SC. Can you replace the battery coolant heater yourself? Easy DIY?

I might just let the car sit for now and see if it fixes itself when the weather warms up (wishful thinking)? Any advice is appreciated. I'm guessing it's gonna go to the SC.

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I had this EXACT issue last year in may with a paltry 5,000 miles on my S. So apparently this battery coolant heater around these years goes bad regardless of miles? Mine was triggered when I tried to put the car into insane + mode. It finally threw the exact 3 bms codes you have. It was then in limp mode until it was fixed by Tesla. Here is the repair sheet.

 

[dwbv]

I had this EXACT issue last year in may with a paltry 5,000 miles on my S. So apparently this battery coolant heater around these years goes bad regardless of miles? Mine was triggered when I tried to put the car into insane + mode. It finally threw the exact 3 bms codes you have. It was then in limp mode until it was fixed by Tesla. Here is the repair sheet.

View attachment 925410

Thanks for sharing and good to know. I'm still waiting to hear back from the SC. It's been like 3 days and not a peep out of them yet.

Do you recall how long it took for the actual work? The SC I made an appointment with is about 2.5 hours away and I'm tempted to just drive the car down there and wait for it to finish and drive it back if the work can be done in one day. This is assuming they come back and actually say it's just the battery heater.

 

[tesluv108]

Thanks for sharing and good to know. I'm still waiting to hear back from the SC. It's been like 3 days and not a peep out of them yet.

Do you recall how long it took for the actual work? The SC I made an appointment with is about 2.5 hours away and I'm tempted to just drive the car down there and wait for it to finish and drive it back if the work can be done in one day. This is assuming they come back and actually say it's just the battery heater.

It was a very fast repair. They had it for one full business day and it was done by the end of that day for pickup. I dropped it off the previous night. Not all service centers are created equal!

 

[Doanster1]

Replacement is easy/quick… it’s how long it takes them to actually get to working on the car that’s long. Hopefully if they know that you’re waiting for it and that you drove 2.5hrs, they’ll get to it sooner rather than later.

 

[KalJoMoS]

It was quick for me too, I handed over at 0900 and the service was done before 3 o’clock. They also had to install the latest firmware to be able to work on the car.

 

[brainhouston]

u can pull the speed sensor out from LDU n check for coolant/moisture there to rule that out.
its a quick DIY.

 

[dwbv]

u can pull the speed sensor out from LDU n check for coolant/moisture there to rule that out.
its a quick DIY.

Please tell me how. I'd love to check. Link please.

 

[brainhouston]

 

[dwbv]

Thank you for this. I suppose dropping coolant levels is also a sign that you may be leaking coolant into the DU? Or wherever else for that matter.

I'm guessing it doesn't take a lot of coolant to cause an issue since coolant shouldn't be in the DU at all, right?

 

[brainhouston]

Thank you for this. I suppose dropping coolant levels is also a sign that you may be leaking coolant into the DU? Or wherever else for that matter.

I'm guessing it doesn't take a lot of coolant to cause an issue since coolant shouldn't be in the DU at all, right?

Yes, i believe some members saw no coolant level decrease but got LDU leak n errors... it doesn't take much...