Bought a non-running Tesla Model S at auction - Have questions

[MVT72]

Hello, I'm new to Tesla motor club. Forgive me for getting to the point and for writing this long essay. My name is Mike and I've always wanted a Tesla but can't afford to buy a used one so I decided to look at public auctions for one. Long story I had a plan to buy 2 used Tesla Model S from auction to rebuild. Auction time came and I was bidding, won the parts car but my luck went out and I wasn't able to secure the running one with body damage. So here I'm stuck with a 2013 Tesla Model S that doesn't do anything. So I figure why don't I try to jump it to see what happens. Hook up the jumpers to the front negative and positive posts and my jumper sees no voltage. I thought it was odd because I have jumped ICE vehicles and even with out a battery, I'm able to jump it. Took the battery out and it measured 0.4 volts. So, I ordered a new battery from Tesla and installed it. Interior powers up and everything but the main screen shows a T logo and stayed there without any progress. Small screen shows low voltage errors and that vehicle will shut down due to low power. So I try to put a jumper onto the 2 post up but again, it's showing 0 voltage, not spark or anything when touching to 2 posts with the jumper so I got a charger on it and still it shows no voltage. Checked the post with a voltmeter to the battery and it shows I have voltage from the ground/negative post to the battery positive but no voltage from the positive post to the battery negative so it looks like I have an issue with the positive post wiring. Then I go into the cabin to find that the main battery shows "full" but with zero (0) miles. I plug in the charger for the high voltage battery and the screen displays "charged completed". I called to talk to Tesla and was told they see a "fault in the 12v battery system" but would not clarify what it is and advice me to bring it in. The problem is their service center is in another city about 2 hours from where I'm at. Initially I was going to use this as a parts vehicle with a wrecked Tesla but now I'm intrigue and want to see how far I can get with this vehicle because the interior and body is in pretty good condition. I have attached some pictures. Hopefully someone here can explain what I'm seeing. How is the positive post line run, what does the full battery indicator with zero miles mean? What's causing the main screen from booting up? Any help is appreciated. Thanks, Mike

 

[brainhouston]

Have u looked under the car? Is hv pack there?
T logo might be emmc issue
Best way is to look at service mode but in ur case only option might be toolbox...
Although I'm not sure if it will even connect with dead MCU
Get SMT or other CAN scanner n see if u can get any details

 

[MVT72]

Hey Brian, thanks for the advice and thanks for correcting my thread title. I'll try to hook up a scanner to see if I can get anything but from reading other post, it seems most users don't get anything from that port. I looked under the car when I was troubleshooting this and I see what seems to be the main hv battery pack, though, I'm not 100% sure the battery is inside. So if the hv battery pack was removed and the shell reinstalled, would the car still tell me that charging is complete when I plug it in to charge? Also, I have overlooked this and I'll have to check later when I get back to the car but would a dv dv converter not supplying voltage to the fuse box on the battery be an indication that the hv battery pack has been removed or could it be that the dv dv converter is bad? Thanks, Mike

 

[j.harris]

The OBD2 port under the steering column doesn't give much data like you said. You need to remove the cubby under the navigation screen to access the CAN bus connector. You will need an adapter that lets you connect to the car's diagnostic connector to a OBD2 connector. The app "Scan My Tesla" is helpful to determine battery information.

 

[MVT72]

J. Harris, thank you for pointing me in the right direction. I will definitely get that adapter and see what I can find out. I did a search for "scan my tesla" and found "scan my t3sla" I'm assuming that's what you're referring to? I'm guessing that I would be able to use scan my tesla to see the error codes and if the hv battery is still inside the pack or not. Thanks again.

 

[SoCal Buzz]

J. Harris, thank you for pointing me in the right direction. I will definitely get that adapter and see what I can find out. I did a search for "scan my tesla" and found "scan my t3sla" I'm assuming that's what you're referring to? I'm guessing that I would be able to use scan my tesla to see the error codes and if the hv battery is still inside the pack or not. Thanks again.

It’s not really practical to take battery out of casing and reinstall shell. If you see battery tray under car and behind front wheels, 99% it’s still there.

 

[j.harris]

I did a search for "scan my tesla" and found "scan my t3sla" I'm assuming that's what you're referring to?

I wasn't aware that it spelled that way for iOS but that seems right.

scan my tesla

'scan my tesla' is an Android app that will connect to a Tesla Model S, 3, X and Y CAN bus, and show and log hundreds of readings. Please note you need a special wiring harness to connect, more details under Adapters. This app gives you numerous live statistics such as: - Battery power / voltage

www.scanmytesla.com

 

[MVT72]

It’s not really practical to take battery out of casing and reinstall shell. If you see battery tray under car and behind front wheels, 99% it’s still there.

SoCal, that gave me some hope. Keeping my fingers crossed.

 

[MVT72]

I wasn't aware that it spelled that way for iOS but that seems right.

scan my tesla

'scan my tesla' is an Android app that will connect to a Tesla Model S, 3, X and Y CAN bus, and show and log hundreds of readings. Please note you need a special wiring harness to connect, more details under Adapters. This app gives you numerous live statistics such as: - Battery power / voltage

www.scanmytesla.com

Just as expected, I hook up the scanner to the obd2 port under the steering wheel and it just recognizes the vehicle but that's it. I couldn't connect to read anything from it. So I ordered the adapter and it's coming in tomorrow. I also downloaded and paid for the app. Hopefully this will give me some useful information. Thanks.

 

[Gtech]

No positive power on positive jump post is a blown fuse which you can find above the 12V battery.

Like already said maybe the emmc inside MCU is busted, if you don't want to involve Tesla you can remove MCU and bring it to someone who can replace emmc chip. Most of the time they can do some diagnose to MCU also even without the car itself since the MCU don't really need the car itself to get the main screen working. It's actually the other way around.

If you have the MCU repaired you can enter service mode and check for some errors.

 

[MVT72]

No positive power on positive jump post is a blown fuse which you can find above the 12V battery.

Like already said maybe the emmc inside MCU is busted, if you don't want to involve Tesla you can remove MCU and bring it to someone who can replace emmc chip. Most of the time they can do some diagnose to MCU also even without the car itself since the MCU don't really need the car itself to get the main screen working. It's actually the other way around.

If you have the MCU repaired you can enter service mode and check for some errors.

so I checked the fuses in the fuse box on top of the battery and all the fuse link seems to be working fine. they all have continuity.. unless there's something else I'm missing or I'm doing something wrong?

 

[Gtech]

so I checked the fuses in the fuse box on top of the battery and all the fuse link seems to be working fine. they all have continuity.. unless there's something else I'm missing or I'm doing something wrong?

There's a hidden compartment below the first row of fuses see F83

 

[MVT72]

There's a hidden compartment below the first row of fuses see F83

View attachment 1033738

Thanks I'll check it out when I get off work today.

 

[MVT72]

So I did a check on 2nd row of fuses and as suggested the 50 amp fuse #F83 is blown. I also received the adapter for the tesla plug to obd2 connection and plug it in and started her up and started getting a bunch of signals for battery and whatnot but I was not able to pull any error logs. I am not sure if it's able to pull any error logs as there's no options in the list of signals to do so. One thing I notice is that the main battery pack has one cell that is reading low at 1.5v and the rest are around 4v. Could the imbalance in that 1 cell cause the car to shut down? Battery shows 387v and dc to dc converter current shows 255 amps? does that look right? It's showing 11.6v output to the 12v, seems low as a supply to charge the 12v battery. One thing that was weird was I got a "battery reduced but ok to drive" error and my backup camera came on but the car wouldn't move. I'm attaching the screenshots in my phone, please help tell me what I'm really looking at. Thanks.

 

[brainhouston]

that code usually means u018/u029 err (have a look at the fb group with same name) but since u have 5v (impossible) n 1.5v (way too low), most likely ur sense wire fell off from one brick or bmb failed (which will give u f107 error in most cases).
good news is that ur actual cells are probably fine but to fix this issue will require to open the pack anyways (hard n tedious job)
fyi, 1 "cell" (aka brick) as u say is actually 74 cells in parallel, n there're 96 of them in 85kwh pack
u do not get details for each of 74, only as a group

and no, SMT can't read codes...

 

[j.harris]

If you can make it to Recell in Texas they should be able to get the car going for you.

Recell

recell-ev.com

 

[MVT72]

that code usually means u018/u029 err (have a look at the fb group with same name) but since u have 5v (impossible) n 1.5v (way too low), most likely ur sense wire fell off from one brick or bmb failed (which will give u f107 error in most cases).
good news is that ur actual cells are probably fine but to fix this issue will require to open the pack anyways (hard n tedious job)
fyi, 1 "cell" (aka brick) as u say is actually 74 cells in parallel, n there're 96 of them in 85kwh pack
u do not get details for each of 74, only as a group

so can I just replace the module containing the bad bmb with a known good module or does it have to be program or balanced after replacing and how do I find the location of the module that has the fail bmb? also, question about the mcu, can I just replace it with an mcu from ebay, would it boot or would it also need to be program. I'm guessing it's much more then just replacing parts. I'm hopping I'll be able to access the errors on the vehicle but more importantly I'll be able to put it into tow mode or release the brake so that I can move it into the shop.. I've read online that some says it needs your original mcu files and others say it boots and works.. not sure what is true. also read that someone was able to put a high amp charger onto their vehicle and bypass the dc dc converter to make the vehicle go into drive, again don't know if that's true...

 

[j.harris]

You're in way over your head on getting this battery fixed. The original MCU from your car has to be read from first to program the new MCU to work with your car. Swapping in another car's MCU won't work. If you do plan to get this car driving again plan to upgrade to the newer MCU2. Tesla will do the upgrade for less than $2,000.

You need to get this car to a shop that knows what to do with it. Either decide if you want to pay to fix it or send it back to auction.

 

[brainhouston]

so can I just replace the module containing the bad bmb with a known good module or does it have to be program or balanced after replacing and how do I find the location of the module that has the fail bmb? also, question about the mcu, can I just replace it with an mcu from ebay, would it boot or would it also need to be program. I'm guessing it's much more then just replacing parts. I'm hopping I'll be able to access the errors on the vehicle but more importantly I'll be able to put it into tow mode or release the brake so that I can move it into the shop.. I've read online that some says it needs your original mcu files and others say it boots and works.. not sure what is true. also read that someone was able to put a high amp charger onto their vehicle and bypass the dc dc converter to make the vehicle go into drive, again don't know if that's true...

u 'can' replace with diff module but it has to be matched in CAC otherwise imbalance will grow n shutdown the pack again later...
but in ur case u might not have to, need to open up the pack n see whats up...
not sure if u noticed but ur brick 30 is missing from SMT screen shot, which is why i think SMT reports standard 5v (aka missing module)
so very possible u lost one sense wire n another on its way out creating high resistance therefore showing only 1.5v...
module layout is known (floating around somewhere), so in ur case 5th module (6 bricks per module) is right under drivers seat area
but its best to ck all bmbs, older packs been known for couple of failed caps...
have a look here:

2014 P85d High Voltage Failure

Unfortunately, I ended up with a HV battery failure last night – 2014 P85D. There were buckets of errors on the screen mostly related to a dead 12v which I hoped was the issue so I replace it. When the car came back on, the errors persisted. ScanMyTesla shows Cell 46 down over a volt and Cell 47...

teslamotorsclub.com

mcu can't be replaced without programming it with ur data but data is stored in both mcu n IC, so even if urs dead u can pull it from ic, then flash that to new mcu1. contact LayZ here via DM, he'll get u anything u need with MCU1
u can put it in 'tow' mode by manually taking off parking brake calipers from rear wheels, i've done it on mine, not too hard at all, take off the wheel undo 3 screws...
high amp charger (aka dual charger) can be physically put in the car (if u don't have one already) n changed in the gateway but has nothing to do with bypassing dc-dc or drive, thats just wrong, unless u talking about external charger which doesn't matter either since u can't charge with error anyways...
if u have any bms errors (which u do) contactors will never close, so no drive or charging, n no dc-dc available to support 12v
u need to educate urself how EVs work in general n tesla specifically

 

[MVT72]

u 'can' replace with diff module but it has to be matched in CAC otherwise imbalance will grow n shutdown the pack again later...
but in ur case u might not have to, need to open up the pack n see whats up...
not sure if u noticed but ur brick 30 is missing from SMT screen shot, which is why i think SMT reports standard 5v (aka missing module)
so very possible u lost one sense wire n another on its way out creating high resistance therefore showing only 1.5v...
module layout is known (floating around somewhere), so in ur case 5th module (6 bricks per module) is right under drivers seat area
but its best to ck all bmbs, older packs been known for couple of failed caps...
have a look here:

2014 P85d High Voltage Failure

Unfortunately, I ended up with a HV battery failure last night – 2014 P85D. There were buckets of errors on the screen mostly related to a dead 12v which I hoped was the issue so I replace it. When the car came back on, the errors persisted. ScanMyTesla shows Cell 46 down over a volt and Cell 47...

teslamotorsclub.com

mcu can't be replaced without programming it with ur data but data is stored in both mcu n IC, so even if urs dead u can pull it from ic, then flash that to new mcu1. contact LayZ here via DM, he'll get u anything u need with MCU1
u can put it in 'tow' mode by manually taking off parking brake calipers from rear wheels, i've done it on mine, not too hard at all, take off the wheel undo 3 screws...
high amp charger (aka dual charger) can be physically put in the car (if u don't have one already) n changed in the gateway but has nothing to do with bypassing dc-dc or drive, thats just wrong, unless u talking about external charger which doesn't matter either since u can't charge with error anyways...
if u have any bms errors (which u do) contactors will never close, so no drive or charging, n no dc-dc available to support 12v
u need to educate urself how EVs work in general n tesla specifically

Hey Brain, appreciate the detail explanation to my questions. As I said initially this vehicle was a parts vehicle for a body damage tesla that I wasn't able to secure. I have been rebuilding ice vehicles for a while and body repair is my thing but I'm new to tesla and it's hv components if that's not obvious yet. You guys have been very helpful and thank you for sharing your knowledge with this newbie. I have learned a lot about my tesla already but will need to continuing educating myself more if I ever want tackle this issue at that level. I was intrigue but I think I'm at the end of my comfort zone. I think my best option is to find a complete p85 battery pack to swap it in or go back to my initial plan of trying to secure a body damage one to rebuild using this parts vehicle. I'll post updates to this when I get to that point. Thanks again!