Model 3 salvage rebuild. The HV stopped working after failed software update. I have a 2021 model 3 RWD.

[Tayne]

I purchased a 2021 model 3 with front damage. I replaced the Pyro fuse, SRS computer, seat belts and airbags. The radiator and shroud and many other parts. Last weekend I had everything working. How ever it stopped work soon after a software update try to install. It said it was unable to complete, however the car shows the software version is new and up to date.
HVP_w015 unable to charge service is required
CP_a016 Unable to charge
UI_a019 parking brake functions degraded
BMS_a179 vehicle may not restart
I unplugged the 12v battery, the first responder loop and the 12v penthouse connector in the back seat. Waited several hours. Plugged them back in (reverse order). It cleared the codes. The coolant pumps turn on (never really stop). The drivers side doors all work. The computer comes on. The passenger side doors/windows never reboot. The HV system doesn’t come online. The car will not shift. The car will not charge. I have repeated the process many times. Last weekend it worked but know it doesn’t. I have recharged the 12v battery contently. I bought a deep cycle full size battery which I also charge and hook the the 12v with jumper cables. I no longer believe it’s a 12v battery issue. The HV just will not engage. Not sure it the second computer is even on. The parking brake will not disengage. Towing mode is greyed out.
Any recommendations would be very welcomed.

 

[qdeathstar]

This is way out of my wheelhouse but my only thought is did they pyrofuse blow again?

 

[Tayne]

I asked that question too but was told the it requires another accident to blow it. It only blows with airbag deployment. I think I bricked the second HV computer. The software update died in near the end of the installation.

 

[Said Ka]

disconnect the hybrid battery plug below the rear seat, and disconnect the low voltage battery. 30min later connect them and retry. This has happened to me on a 2022 Model 3 AWD.

 

[MP3Mike]

Have you tried reinstalling the update while having the 12v battery supported?

 

[Mapky1]

go to the service menu and reforge software install. Be sure your 12v source and battery is adequate (even supply an external supply to ensure). And prior to forcing a reinstall. Check the service alerts in the service screen. It details a lot more information!!!

 

[PlaidSpeed]

Did you figure it out?

 

[Tayne]

Thanks for the feedback. I took me a bit to get it all done. The front middle impact sensor was a bit of an issue because the I didn’t get any mount for this sensor. Tesla doesn’t sell it separately. I bought one off EBay however for my 2021 it’s a different sensor and mount. The parts guy at my service center was able to verify it is the black mount and the impact sensor marked with a 2.

Once I fit that I was hoping it would be done. The final code was the the left front sensor. I replaced it with a new one from Tesla. Again hoping it would fix it. The code changed 1 digit. Which said there was a short. I thought it might be the emergency frunk wires shorting. I wrapped the leads in tape. Disconnected the 12v and HV connections. On reboot it still found the same codes took it to Tesla they charged another $500. Found the new sensor I installed had a short internally. They reloaded some firmware updates and got it working. So finally it’s all working after spending $6K at Tesla. With all the work they did and testing. Should see if they will add my SC inspection as part of what they did.
Thankfully it’s finally working.

 

[evrepair]

$6k? Glad you got it fixed though.

 

[davewill]

Thanks for the feedback. I took me a bit to get it all done. The front middle impact sensor was a bit of an issue because the I didn’t get any mount for this sensor. Tesla doesn’t sell it separately. I bought one off EBay however for my 2021 it’s a different sensor and mount. The parts guy at my service center was able to verify it is the black mount and the impact sensor marked with a 2.

Once I fit that I was hoping it would be done. The final code was the the left front sensor. I replaced it with a new one from Tesla. Again hoping it would fix it. The code changed 1 digit. Which said there was a short. I thought it might be the emergency frunk wires shorting. I wrapped the leads in tape. Disconnected the 12v and HV connections. On reboot it still found the same codes took it to Tesla they charged another $500. Found the new sensor I installed had a short internally. They reloaded some firmware updates and got it working. So finally it’s all working after spending $6K at Tesla. With all the work they did and testing. Should see if they will add my SC inspection as part of what they did.
Thankfully it’s finally working.

So Tesla sold you the faulty sensor? Seems like they should have covered the diagnosis and replacement part.

 

[nicksp]

Thanks for the feedback. I took me a bit to get it all done. The front middle impact sensor was a bit of an issue because the I didn’t get any mount for this sensor. Tesla doesn’t sell it separately. I bought one off EBay however for my 2021 it’s a different sensor and mount. The parts guy at my service center was able to verify it is the black mount and the impact sensor marked with a 2.

Once I fit that I was hoping it would be done. The final code was the the left front sensor. I replaced it with a new one from Tesla. Again hoping it would fix it. The code changed 1 digit. Which said there was a short. I thought it might be the emergency frunk wires shorting. I wrapped the leads in tape. Disconnected the 12v and HV connections. On reboot it still found the same codes took it to Tesla they charged another $500. Found the new sensor I installed had a short internally. They reloaded some firmware updates and got it working. So finally it’s all working after spending $6K at Tesla. With all the work they did and testing. Should see if they will add my SC inspection as part of what they did.
Thankfully it’s finally working.

How much did you originally buy the car for?