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Rebuilding Salvaged Model S 75D

Alexandru G

Nov 9, 2020
I'm rebuilding my second Tesla Model S; if you're interested in my first rebuild experience, see here. This is a 2017 (December build) 75D with 4k miles.

So the first thing I did after moving the car into the garage was replace the pyrofuse and connect the cut loop. I gave the battery a jump although eventually the dcdc fully charged the 12v battery and the car was operating on its own power. Off to a good start.

View attachment 353431

Unfortunately though, what comes next is not as glamorous...

I decided to put the car in drive to back out of my driveway and then back-in again. That was fine. Although next, I decided to see if the car chargers, so I connected the HPWC and the car began charging! However, after 5-10 minutes the car stopped charging and I noticed the charge port was red.

View attachment 353435

I then made the unfortunate discovery the car was extremely low on coolant. So I decided not to touch anything until I installed a new radiator and added G-48 coolant. This is mistake #1.

In the meantime however, I noticed an update from Tesla, so I decided to perform the update. This is mistake #2. Evidently, you should never perform an update on your car if it's still undergoing repairs and all ECU interfacing components are not connected. I suppose this seems obvious in retrospect, but nevertheless something to always keep-in-mind. So, naturally, the software update failed. Although, the update seemed to have flashed some components, but not all. So, I started seeing this error:

View attachment 353437

Well, this sucks. The car will not drive anymore. In addition, the contactors are not closing and the dcdc is not charging the 12v anymore. Also, asking Tesla to send me an OTA will not work since the car is salvaged. So, I had to rely on my software engineer background and help from some members to gain access to the car and derive a bit more information, but first, I tried the update again from factory/developer mode:

View attachment 353440

Here are the syslogs.

Some notable references from the logs:
gwmon 10261: BMS contactor close request
gwmon 15444: timeout - BMS contactors did not close, ctr state OPEN (0)
gwmon DCDC NOT present, NOT updateable (NO bootId, NO versionMsg, NOT enabled), BMS contactors NOT closed
gwmon chgph1: no hwid

As you can tell, the BMS, DCDC, and Charger are not responding, which contributed to the upgrade failure. Here is a list of diagnostic errors I'm seeing:

View attachment 353443

It seemed suspicious the on-board charger was MIA, so I figured there could be a blown fuse. Will expand on this in the next post.
Hi how you access Syslog ?
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Jul 30, 2019
Dayton, OH, United States
Does anyone know where I can purchase replacement Model - S - Passenger Airbag Connectors that I can splice into the wire harness. I am replacing the instrument panel with a new one with the passenger airbag module attached. The old instrument panel deployed the airbag module and the wire harness connectors melted into the old deployed module. I am looking for some new pigtail inflator connections that fit the passenger airbag module.

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