Salvage 2022 Model Y LR. High Voltage Battery contactors not closing. Car has the new Li-Ion 12v battery.

[Sergiidt]

Dealing with same thing 2021 Tesla model s plaid . But in my car one HV cable for rear motor disconnected from main battery and I can’t find new cable . Check if on your car cable from rear motor to battery not damaged

 

[Nintendo80]

I did not... I will try now. thanks for the TIP.

 

[Nintendo80]

Just checked wire all good Sir…

 

[Sergiidt]

Just checked wire all good Sir…

New teslas don’t have fuses. I think they made new protection system which after accident burn pyro-fuse, disable 12V battery and register in memory car had accident and back to life need to change pyro fuse, 12v battery and re-fresh one of the module to start a car . ( that’s just my mind)
What I gonna do with my car
1) Gonna try find hv cable which broken and make car driving with my knowledge.
2) Try to find and ask for help Ingineerix on a YouTube (looks like this guy know everything about Tesla)
3) gonna drop car to tesla pay for high voltage inspection and fixed cable and do everything what they need to make car running
As soonest as find some solution gonna write here .

 

[Omaraied]

Double check these grounds are tight when installing the cover

 

[ShawnA]

Hi All,

This is a good resource regarding the new lithium low voltage battery...

In the first few pages there are a few pictures with voltmeters that show
the voltage as 15.48 VDC

2021 Refresh: Model S (and X?) Changes to 12v System

Buried in one of the Model S sticky threads, there was a post by a guy wondering why his Escort radar detector was throwing "High Voltage" warnings on his new 2021 Refresh Model S. The short version of this story is that the Refresh cars have a fairly significant change to the 12v (let's call...

teslamotorsclub.com

To make the systems perform as designed the voltage should be in the neighborhood of 15.5 VDC
to make contactors close and to eliminate "battery not connected" messages...

Good luck,

Shawn

 

[Nintendo80]

Yes is true I had to buy a 12-24V maintainer to keep the car alive. However there must be something else that happen when the car crash besides pyro fuse and srs module because the car is equipped with 15.5 V battery and still does not close contactors and keep saying electrical system power reduced. “vehicle load shedding is active; or reverse battery transistor issue detected”.

 

[Said Ka]

Hi All,

The car had a rear end damage (R Bumper, Liftgate):

1. Pyro fuse was blown: Have replaced
2. Driver side Seat belt restraint stuck: Not yet repaired/replaced
3. All Airbags are good

• After the Pyro fuse was replaced, the charge port light has turned from Red to Blue but the car still won't charge. Occasionally I am able to click on the screen to “Start Charging”. The button momentarily turns gray (unclickable) but doesn’t charge and then the button returns to active but not clickable anymore. The car shows maintaining 260 miles of charge
• The 12v battery drains and dies in few minutes with these messages. I also got a new 12v Li-Ion battery from Tesla and that too died shortly. Now I am using an external Lead Acid.
  • VCFRONT_a478 Schedule Service – Vehicle may not restart
  • VCFRONT_a402 Electrical system backup power is unavailable - Vehicle will consume more energy while idle
  • VCFRONT_a192 Electrical system is unable to support all features – shutting down features to conserve energy
  • VCFRONT_a191 Electrical system power reduced - Vehicle shutting down
• On connecting the 12v battery, I can hear the usual low sounds and the screen turns on. I can put the car in “Transport Mode” and the EPB works fine.
• But I do not hear the High Voltage Battery contactors closing sound and this is the likely the problem (and so the message VCFRONT_a402 Electrical system backup power is unavailable)

Trying to figure out. Didn't find any shorts or severed wires (except for the parking sensor harness on the Rear bumper which has been disconnected).

Appreciate any Help.

HI, have you found the problem? Can you give us a quick update? I have the exact same problem, same codes, same replaced pyro fuse, airbags and seatbelts, everything good, but brand new ion lithium battery got drained in no time.

 

[Nintendo80]

Not yet Man,
I checked all the tesla repair manuals and tried all the Tool box 3 menu available from the tesla software. No luck. I will keep you posted if I find something please do the same. Thanks

 

[Said Ka]

Not yet Man,
I checked all the tesla repair manuals and tried all the Tool box 3 menu available from the tesla software. No luck. I will keep you posted if I find something please do the same. Thanks

ok im troubleshooting on my end too. will update you as well if I find the fix!

 

[Nintendo80]

Same here I’m running some test tonight too

 

[Said Ka]

hey! I may (or may not) have found the solution to the problem. Click here then go to min 4:15. Thats what may be stopping our teslas from starting what do you think?

 

[Nintendo80]

When are u going to try? I can’t today unfortunately.

 

[Said Ka]

I dont have the software. Waiting for a dude to come with his tools. Ill keep you posted.

 

[Nintendo80]

Nope does not work!!!

 

[Nintendo80]

I know a dude if u need a contact let me know…

 

[Said Ka]

I know a dude if u need a contact let me know…

Also confirmed clearing the BMS isolation alert counters won't fix it. My guy did it but he told me ahead of doing it that the M3 clears them automatically. The model S needs them cleared, not the M3. Continuing to diagnose. Pls keep us posted as well.

 

[amousa]

any update guys same issue here, I do have the software, codes below

BMS_a179

BMS_a128

VCFRONT_a478

VCFRONT_a402

VCFRONT_a192

VCFRONT_a191

 

[amousa]

Okay, so this is what I learnt:

Pin 5 on the battery is a LIN pin communicating with the car. When the car (master) senses Low Power, it sends a SLEEP MODE COMMAND to the slave (12v Li-Ion battery) to go to a "Low-power mode operation" and disables the LIN Bus. The battery MCU is still operational and the LIN can receive commands but cannot send until a wake-up event. Due to this, the battery won't even charge (unlike Lead Acid) even if the the car is now running, or you have the charger connected or the HV battery is supplying power.

Two choices at this point:
1. Wake-up the battery LIN (which I haven't figured yet)
2. Buy a new 12v Li-Ion battery from Tesla (obviously it will have the LIN communicating) even though your battery isn't dead/bad. It's just on a low power protection mode.

I see two Potential Problems:
1. Similar to my case, in an accident, the Pyro fuse will blow and HV battery will disconnect. The 12v Li-Ion will last you 30 minutes and then go to sleep unless you disconnect it. I saw that the car does warn how much power is left on the 12v until 5% remaining and then shuts off.

2. For any reason (maintenance or so) you disconnect the HV First Responders' Loop but leave the 12v connected, you should watch the car's screen and not let the 12v go to sleep.

I have a Model Y from Dec 2021 that has a 12v Lead Acid. The car in the above reference is a Model Y from Jan 2022 and has this new 12v Li-Ion. So I am assuming all Model Ys after Jan 2022 may have the Li-Ion 12v.

Thought I should share. Hope this helps some one..

@UShe any updates, you had this for several months and I wish your issue is resolved; I have the same issue with model 3

 

[Nintendo80]

any update guys same issue here, I do have the software, codes below

BMS_a179

BMS_a128

VCFRONT_a478

VCFRONT_a402

VCFRONT_a192

VCFRONT_a191

yes man replace vcfront and everything will go away. just solved that issue on mine.