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12v System Failure While Driving

TomServo

Active Member
Apr 10, 2014
1,750
1,174
Belleville IL
This is BAD news GOOD news story given the quickness of the failure and circumstances the owner had to deal with. When we travel we carry a small A23 12V battery with us (my wife carries it in her purse) should we need to get to the jump start wires located behind the tow hook cap to at least unlock the car. Still looking for a temp place to stow it on the exterior, but it's small enough to carry in a pocket. This is the USAF in me.
 

cfisher

New Member
Jul 13, 2021
2
7
Tampa
I had the same thing happen to my MYLR 6 days after taking delivery. Our car broke down 100 miles from home. When we went to get back into it, the car wouldn't start. Same warnings as you. They towed the car to a dealer that was only a couple of miles away. After that everything was a pure nightmare. Even though roadside assistance said the dealer would work on the car, when we got there they were reluctant to do so. They wanted to give us Uber credits to get home. Ultimately, they did try to swap out the 12v but it didn't work and they gave us a loaner. It took a week to replace the Power Conversion System. It was very difficult to get information from the repair shop or to get any support from Tesla. My feeling at the end is that Elon Musk has imprinted his personality disorder on the entire company. Tesla did exactly nothing to make the situation easier/better. All of that being said, we love our new Model Y. The only comfort was that in searching for Power Conversion System failures, I could not find much discussion. I'm glad that not many people are having to deal with this.
 

RowdyMY

Member
Jun 21, 2021
151
315
Raleigh
is PCS the system for DC to DC power converter?
It's not listed in the owner's manual that I could find. If someone has a more thorough understanding please feel free to correct.

The PCS is an LRU that sits on the main battery. Primary functions are to convert AC to DC for charging and 400v>12v for the 12v bus. It's modular in that there are a couple of subsystems that make up the PCS but the entire system is contained inside one singular LRU.

@Rice&Curry
 
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Reactions: boingolover

jcanoe

Active Member
Oct 2, 2020
4,374
4,546
Maryland
It's not listed in the owner's manual that I could find. If someone has a more thorough understanding please feel free to correct.

The PCS is an LRU that sits on the main battery. Primary functions are to convert AC to DC for charging and 400v>12v for the 12v bus. It's modular in that there are a couple of subsystems that make up the PCS but the entire system is contained inside one singular LRU.

@Rice&Curry
This might be detailed in the Tesla parts catalog: Parts Catalog

You should be able to log in, search the catalog using your Tesla account credentials.
 
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Reactions: boingolover

Rice&Curry

Member
May 9, 2018
509
262
San Jose
I had the same thing happen to my MYLR 6 days after taking delivery. Our car broke down 100 miles from home. When we went to get back into it, the car wouldn't start. Same warnings as you. They towed the car to a dealer that was only a couple of miles away. After that everything was a pure nightmare. Even though roadside assistance said the dealer would work on the car, when we got there they were reluctant to do so. They wanted to give us Uber credits to get home. Ultimately, they did try to swap out the 12v but it didn't work and they gave us a loaner. It took a week to replace the Power Conversion System. It was very difficult to get information from the repair shop or to get any support from Tesla. My feeling at the end is that Elon Musk has imprinted his personality disorder on the entire company. Tesla did exactly nothing to make the situation easier/better. All of that being said, we love our new Model Y. The only comfort was that in searching for Power Conversion System failures, I could not find much discussion. I'm glad that not many people are having to deal with this.
The worrying thing is why is a new vehicle facing such problems- is the internal QC of the LRU's and other subsystems so poor that they are entering the production line? Much as I love Tesla cars, I am really getting concerned that they may be cutting corners as they scale up production to keep Wall Street happy.
 

boingolover

Late 2021 Blue on White MYLR 5 w/ tow
Aug 16, 2021
385
1,264
Nashville Area
The worrying thing is why is a new vehicle facing such problems- is the internal QC of the LRU's and other subsystems so poor that they are entering the production line? Much as I love Tesla cars, I am really getting concerned that they may be cutting corners as they scale up production to keep Wall Street happy.
I agree with you to a point, but every vehicle will have some failures. And a lot of times with electronics, it will fail early if it's going to fail. I think the main thing to pay attention to is what the manufacturer does when it fails.
 

Rocky_H

Well-Known Member
Feb 19, 2015
7,297
8,989
Boise, ID
Have you done a lot of dog mode and camping mode? I think using an AC/ heater while the car is not running wears out the battery fast.
You're trying to say that would affect the 12V battery system? No, it wouldn't. A/C and heating always run from the main battery. The 12V system is not relevant to that.
 

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