2014 Model S P85 not charging.

[magnusbjork]

Dear all, I just bought a 2014 Tesla Model S P85 with dual onboard chargers, that the previous owner did not want to fix anymore. It has 270'000 km, the rear motor was changed at Tesla in August 2022, the battery was tested good a few weeks ago, but currently the SoC is at 0%, since a few days, due to charging not being possible.

Once I got the car home, on my car trailer, I started investigating it a bit further. I am located just outside Geneva, Switzerland, so the charge port is a 3-phase model, non-motorized (gen1).

The problem is, the charge port will not open, and the main battery is currently a 0% so I would (of course) like to charge it as soon as possible. The 12V battery was also empty, after the HV battery dropped too low.

I currently have a classic lead-acid battery connected to the terminals behind the nosecone, and a battery charger connected, so the 12V is up and running again.

When I push the "unlock charge port" on the screen, I can hear the HV relays clicking inside the car, but the port just does not open. If I (gently) pry the charge door open and use the manual release of the locking tab from inside the trunk, I can insert the charge cable, but the car refuses to start charging, since I can't use the "manual opening" to start charging.

The fault codes, first readout, after connecting the external 12V battery in parallel are these:
BMS_u008_limpMode
BMS_w172_SW_Drive_Iso_Warning

I had a look inside the HV Junction Box, all fuses are intact and all looks visually ok.

To go a bit further, I found a diagnostics cable, bought toolbox3 access for an hour, installed the proxy, allowed insecure access in Chrome for toolbox and by entering "Service Mode Plus", I could read the following, adding some info;

BMS_w172_SW_Drive_Iso_Warning = The BMS has detected isolation failure conditions in multiple drive cycles.
BMS_w137_SW_Brick_UV_Warning = Brick voltage under warning threshold
BMS_w069_SW_Low_Power = Description is the same as the fault code
CHGS_d001_replace_Charger = Description is the same as the fault code

Ok... So could it be that I have a fault in one of my onboard chargers?

Any and all help greatly appreciated... I am a computer engineer and I have worked on cars as a hobby for over 30 years, and I would like to get a much deeper understanding on the Teslas, in particular the Model S. Except the TMS P85, I also have a TMS P100D(L), and my wife a TMS 90D.

Thanks again.

Cheers,
Magnus

 

[magnusbjork]

 

[magnusbjork]

Can't edit my original message, but I just thought a bit about the fault code "CHGS...". Does this mean "Charger Slave"? And if so, can I simply disconnect the second charger to see if it's this one causing the problems with the "state machine" of the charging sequence, and preventing the opening of the chatge door, and perhaps, could this charger have some problem with the insulation, causing the "BMS_w172"?

 

[magnusbjork]

 

[brainhouston]

w137 n w069 can be ignored for now, its due to low SOC

charger err def could prevent charge port operation n charging so need to take care of this 1st
idk the layout of dual chargers but i'm sure its possible to remove n bypass since cars came with single charger also
but u might need to change some HV n HVIL wiring which could be dangerous if u don't have the original ones
plus software needs to be changed for single charger, might not be worth the effort...

now w172 could be a 2nd issue, unless bad charger is somehow shorting to ground...
most likely culprit is the LDU... ck the speed sensor for coolant...
this one can also prevent charging.... but shouldn't prevent charge port operation "i think"...

 

[magnusbjork]

Here's a little update:

...I have bought, charged and installed a new 12V battery from Tesla, (external 12V charger currently connected). I tried upgrading to a Gen 1.5 charge port, upgraded SW, calibrated with TBX3, still won't open.

I put the Gen 1.5 charge port back on my 2016,5 TMS P100DL, and reinstalled the SW back for the Gen 1.0 charge port.

When I try the screen, key, app, I get a very slight "click" and a message "Please wait while system performs check", but the port never opens.

Of course, if I manually open the port and unlock it with the lever from the trunk, charging is not allowed.

When I checked under service mode, I currently get the following fault codes, see picture.

Any and all hints and suggestions are very welcome, I would really like to save this car...

Thank you.

 

[Gtech]

Here's a little update:

...I have bought, charged and installed a new 12V battery from Tesla, (external 12V charger currently connected). I tried upgrading to a Gen 1.5 charge port, upgraded SW, calibrated with TBX3, still won't open.

I put the Gen 1.5 charge port back on my 2016,5 TMS P100DL, and reinstalled the SW back for the Gen 1.0 charge port.

When I try the screen, key, app, I get a very slight "click" and a message "Please wait while system performs check", but the port never opens.

Of course, if I manually open the port and unlock it with the lever from the trunk, charging is not allowed.

When I checked under service mode, I currently get the following fault codes, see picture.

Any and all hints and suggestions are very welcome, I would really like to save this car...

Thank you.

Like @brainhouston was saying I also would take care of the charger issue first, if chargers aren't working correctly the chargeport will not work properly. I guess change config to single charger+ remove it and fix hvil or swap slave with a known good one would be my best guess

 

[magnusbjork]

Like @brainhouston was saying I also would take care of the charger issue first, if chargers aren't working correctly the chargeport will not work properly. I guess change config to single charger+ remove it and fix hvil or swap slave with a known good one would be my best guess

Thanks for your kind reply. However, I'm not sure if I can trust the "old" fault codes that appeared when the 12V battery was dead? I would guess that quite a few parts would complain about some random issue when the 12V failed.

Now that I have a properly working 12V battery, I basically have no fault code except the 12V support not working. (Logical, since the DC/DC isn't working when the HV battery is at 0%).

If the charger is indeed broken, wouldn't it (still) report a fault code?

 

[Gtech]

Thanks for your kind reply. However, I'm not sure if I can trust the "old" fault codes that appeared when the 12V battery was dead? I would guess that quite a few parts would complain about some random issue when the 12V failed.

Now that I have a properly working 12V battery, I basically have no fault code except the 12V support not working. (Logical, since the DC/DC isn't working when the HV battery is at 0%).

If the charger is indeed broken, wouldn't it (still) report a fault code?

Good question because normally this code comes with another code why 12V isn't supported (also if SoC is to low)

Did you tried changing wheel size 19'->21' to force a deep reset? Assuming it has an old MCU. After that you still have same code?

 

[magnusbjork]

Good question because normally this code comes with another code why 12V isn't supported (also if SoC is to low)

Did you tried changing wheel size 19'->21' to force a deep reset? Assuming it has an old MCU. After that you still have same code?

 

[magnusbjork]

I sometimes also got;

BMS_f071_SW_SM_TransCon_Not_Met = Description: "A requested BMS_state transition was not completed succsessfully." / Set Condition: "A stateRequest from the main BMS state machine has not matured within the expected time limit." / Clear Condition: "Any succsessful BMS_State transition." / Potential Impact: "Pack contactors may not be closed as expected."

Perhaps the "BMS_f071" could explain that the BMS doesn't close the contactors, and in consequence, doesn't allow the charge port flap to open?

I did a lot of reboots, redeployments (reinstall) of SW, checks with toolbox, etc... But, always the same problem. Unfortunately.

 

[tdigsi]

Start with this one first: BMS_w172_SW_Drive_Iso_Warning

 

[Cory02trucks]

I sometimes also got;

BMS_f071_SW_SM_TransCon_Not_Met = Description: "A requested BMS_state transition was not completed succsessfully." / Set Condition: "A stateRequest from the main BMS state machine has not matured within the expected time limit." / Clear Condition: "Any succsessful BMS_State transition." / Potential Impact: "Pack contactors may not be closed as expected."

Perhaps the "BMS_f071" could explain that the BMS doesn't close the contactors, and in consequence, doesn't allow the charge port flap to open?

I did a lot of reboots, redeployments (reinstall) of SW, checks with toolbox, etc... But, always the same problem. Unfortunately.

Have you found a solution?

I sometimes also got;

BMS_f071_SW_SM_TransCon_Not_Met = Description: "A requested BMS_state transition was not completed succsessfully." / Set Condition: "A stateRequest from the main BMS state machine has not matured within the expected time limit." / Clear Condition: "Any succsessful BMS_State transition." / Potential Impact: "Pack contactors may not be closed as expected."

Perhaps the "BMS_f071" could explain that the BMS doesn't close the contactors, and in consequence, doesn't allow the charge port flap to open?

I did a lot of reboots, redeployments (reinstall) of SW, checks with toolbox, etc... But, always the same problem. Unfortunately.

Have you figured out a solution? I am having a similar issue. Thank you.