My Model Y is completely dead after the new vc front

[Aguyfromcali]

Hello,

I bought a rear ended tesla model y awd from auction. The car was stuck in service mode so I started troubleshooting. I changed the pyro fuse and lv battery on it thinking that it would fix the issue. After turning on, I wanted to enter the service mode to clear the post crash load shed, then the service mode kept spinning and nothing happened so I changed the vc front. Finally, After changing the vc front (bought used) I connected the car to an external power supply, service mode showed up, and reinstalled the software. after installation, when it rebooted, it burnt 3 of the power supplies, on the forth one, I wanted to clear the post-crash and the car just shut down. The power supply is good, but the car is just unresponsive. no sparks when I connect the external power. I checked pyro fuse and its good. The lv battery is also ok. Im thinking there is another fuse that is burnt or maybe the vc front is burnt. Is it possible that the vc front that I bought was faulty?

any thoughts?

 

[FatFalcon]

Service mode wasn't loading, so you changed the VCFront? That doesn't make sense... VCFront mostly distributes power, it has nothing to do with the UI. Put back in your old VCFront.

You should definitely stop connecting power supplies. While it's possible the 'new' VCfront is shorted internally, it's also quite possible that the low-voltage maintainer/ support/power supply is not strong enough to support the low-voltage system and that's why they are burning up.

I will also note that if the low-voltage system is struggling lots of things on these cars won't work right, including the screen being buggy. You need to put in a good 12V battery and have a proper power supply hooked up before doing any troubleshooting.

 

[Aguyfromcali]

Service mode wasn't loading, so you changed the VCFront? That doesn't make sense... VCFront mostly distributes power, it has nothing to do with the UI. Put back in your old VCFront.

You should definitely stop connecting power supplies. While it's possible the 'new' VCfront is shorted internally, it's also quite possible that the low-voltage maintainer/ support/power supply is not strong enough to support the low-voltage system and that's why they are burning up.

@FatFalcon Thank you for your reply. I watched a YouTube video that they had the same issue with the service menu spinning and they changed the vc front and it went away.

 

[evrepair]

2022+ car with lithium Lv right?

what power supplies are you using? They shouldn’t get burned. You need 40A preferably 50A power supply. Voltage between 12 and 15V.

Service mode not loading = car is in load shed mode. So yeah need to either reset it or replace the vcfront and do a software reinstall, so you did right except I think you have bad power supplies .