Help! Car won't reboot and the A/C is stuck on

[Nicky5452]

Don't worry I won't leave you all hanging.

Update: they "think" the issue is the driver inverter. But the issues are they can't read the vehicle logs. The car stopped sending logs on Sep 1st, and the car has been on (wouldn't sleep) for four days so it needs a new 12V at the least. The last error received was the car incessantly reading that the parking break was stuck. I think that's why he thinks it was the driver inverter. I agree with most above, I think it's more than that.

They didn't do any diagnostics yesterday. It's too dead and the shop was backed up I guess. He said I wouldn't know anything until today, when they see if they can get logs from it.

Right now I have a model S, P85 loaner. At least I am not stranded. The SC was really nice and got me in and out pretty smoothly. They lastly left me with worse case scenario I will have a loaner 2 weeks, if the parts aren't on island.

 

[SMAlset]

Never good when stuff happens especially when it impacts you personally. Glad to hear they were able to set you up with a loaner and hope your wait isn't long. Thanks for the update. Have you driven an MS before? Might take a little adjusting to. I'm always more cautious when it comes to parking our MS but there are a number of things I like more about the car too. Will be curious how you will compare the experience to your Model 3 if you have it for more than a few days.

 

[Nicky5452]

Update: as of today the service rep says,
"The RAM encountered an error which it is unable to recover from. This is extremely rare. We have determined that the car will need a new computer and one has been ordered for your vehicle. We do not have one in stock at this time. I estimate it should be here by Wednesday. "

I will let you know if there are any other updates to the errors as well as provide my full review of driving a 2014 Model S P85 versus my 2019 Model 3.

 

[SMAlset]

Can't say I've read that happening before. Thanks for the update and guess you get to experience the P85 a bit longer.

 

[Daniel in SD]

I would be concerned about the possibility that the main battery was deeply discharged.

 

[Lunares]

Update: as of today the service rep says,
"The RAM encountered an error which it is unable to recover from. This is extremely rare. We have determined that the car will need a new computer and one has been ordered for your vehicle. We do not have one in stock at this time. I estimate it should be here by Wednesday. "

I will let you know if there are any other updates to the errors as well as provide my full review of driving a 2014 Model S P85 versus my 2019 Model 3.

So yep broken MCU. that's about all I could think of.

I would be concerned about the possibility that the main battery was deeply discharged.

Highly unlikely.

is a battery pack teardown. BMS is built into the modules themselves, not the MCU.

With a broken MCU the car would keep drawing power from the pack and ignore the normal signals to stop doing so. But the "do not cross this line" programming is going to be in the BMS itself. At a certain point the BMS will throw the contactor into the off position, at which point the MCU will stop drawing power.

It's no different from ignoring the warnings and driving until the car shuts itself off. Tesla doesn't let you damage the pack with a single deep discharge like that. It is true that if you kept a load on the pack you could discharge the cells to the point where they are damaged. And that repeatedly deep discharging is bad. The BMS stops the first one, and this only one event so the latter isn't a concern either.

 

[dmurphy]

Update: as of today the service rep says,
"The RAM encountered an error which it is unable to recover from. This is extremely rare. We have determined that the car will need a new computer and one has been ordered for your vehicle. We do not have one in stock at this time. I estimate it should be here by Wednesday. "

It probably won’t make you feel any better, but I sell, service & support multi-million dollar servers. And memory errors absolutely are a thing. It happens. Unfortunately you drew the short straw and are stuck with dealing with it. Sorry for that.

The good news is that they’ve diagnosed it, know the root cause, and got you into a loaner. Those are all good things, about as good as one can expect.

Keep us posted!

 

[RedModel3]

In the future, know that something like this, or in my case even a nail in a tire at home, is certainly what the emergency roadside assistance is for. I've had my car for over a year, and I just don't call the regular number anymore. It's either drive directly to the SC or call roadside assistance (I've only had to do that once.)

I'm happy for you that you go this diagnosed, and it should be covered under warranty. Hope you get your baby back soon!

 

[Daniel in SD]

So yep broken MCU. that's about all I could think of.



Highly unlikely.

is a battery pack teardown. BMS is built into the modules themselves, not the MCU.

With a broken MCU the car would keep drawing power from the pack and ignore the normal signals to stop doing so. But the "do not cross this line" programming is going to be in the BMS itself. At a certain point the BMS will throw the contactor into the off position, at which point the MCU will stop drawing power.

It's no different from ignoring the warnings and driving until the car shuts itself off. Tesla doesn't let you damage the pack with a single deep discharge like that. It is true that if you kept a load on the pack you could discharge the cells to the point where they are damaged. And that repeatedly deep discharging is bad. The BMS stops the first one, and this only one event so the latter isn't a concern either.

Possibly, but now it’s sitting at a charge level below 0 miles for who knows how long. I’ve always heard that leaving it at a low SoC is bad for the battery.

 

[Kalia]

Roadside assistance is supposed to be open 24/7. This definitely qualifies for calling them.

I tried calling roadside assistance with the same problem, and they said they only do tows.