2014 Model S - Continued high voltage problems

[FrozenCanuck]

Hey gang,

I’m wondering if you can chime in on this. Normal? Acceptable? What can I do to communicate my expectations to Tesla service?

The issue:

• Since late November my Model S has refused to start 3 times now.
• Each time I got a “needs service” message, and I had to take the car in, have it “fixed” and then returned to me.
• The faults were always related to the HV pack, but different warnings and they were always intermittent
• So each time I was stuck, the car would eventually start later … with time as the only variable.
• Tesla “repaired” it twice. First time they gave me a new drive unit.
  • That makes zero sense to me because a HVDC issue is unrelated to an AC motor. It’s on the other side of the inverter.
  • I suspect that “repair” was not necessary and they may have also fixed a loose / corroded connection
  • Second “repair” was a loose connector pin. Several hundred dollars later.
  • Now, only 4 weeks later, I’m again stuck with a car I do not trust, wouldn’t start last night with the BMS f008 error message “car may not start”. This happened during charging in my garage. It stopped charging after about 30 minutes and this error was present. Let it sit overnight and now it will work again (charging as I type this)

It just feels like Tesla is not actually fixing the problem. This should not be that difficult to fix. Should it?

I do not want to feel like I can’t trust this car. But that’s what’s happening. I’m hesitant to have my kids drive it.

 

[Gixx1300R]

Have your 12 volt battery tested

 

[Plasmid_Boy]

I have had BMS errors caused by coolant leak in motor, shorted AC compressor, shorted heater, shorted battery heater, and bad HV battery contactor.

I remember seeing a post about the charger causing it too (below).

Good luck and please do update.

Fault codes reference table? w008 f008

Hi guys, I was wondering if anyone has a table of tesla fault codes that they are willing to share with me, I recently repaired an isolation fault which i could work out with the relevant diagnostics computers I have but one there is virtually no info out there of what these faults relate...

teslamotorsclub.com

 

[FrozenCanuck]

Have your 12 volt battery tested

Would a 12V battery issue trigger HVIL warnings, though?

I'm not debating, I'm just asking, as I currently don't understand how that makes sense, but I'm not en electrical engineer so I may just lack some knowledge here.

 

[FrozenCanuck]

Have your 12 volt battery tested

Ok, I don’t exactly know how to test the battery but I pulled my nosecone and threw a multimeter on the battery terminals. I’m getting 12.7VDC. That seems normal, right?

 

[FrozenCanuck]

Quick update: The alerts cleared temporarily so I could drive the car to the service center. While driving the alerts came back 3-4 times and cleared briefly each time.

Definitely another intermittent issue

 

[PCMc]

Most all the diagnostics will reset on start-up and run again. That's why in intermittent situations like this you'll see errors go away after car shut off for a bit. That's annoying in the case of intermittent cases where you'll see the faults come and go, not always being active when you take the car in for service.

The OBD regulations actually have provisions to try and minimize this. Once you trip a fault that illuminates the MIL, you need to have two complete drive cycles of a minimum duration before the light and the fault can be cleared (even then, there are tell tale snapshots saved which scan tools can access). The ODB regulations are actually a subset of the gaseous emissions regulations, and Tesla as a pure BEV is not subject to comply with any of these regs.

While many are annoyed by the MIL / Check Engine Light and would like for it to not exist, it's instances like this where some of those regulations actually can benefit owners.

Beyond that, nothing I can add versus the comments others have provided. Hopefully Tesla can get to the real root cause (or causes?) to end your frustration. I know i I was in you're situation I'd certainly be frustrated.

 

[The Lorax]

Had a bunch of mystery HV BMS codes come up a few months ago. "Car needs service. Car may not restart" etc. SC replaced one of the HV cables to the rear motor and has been fine ever since.

 

[FrozenCanuck]

Brief update here.

It looks like I really did have 3 separate issues triggering HVIL warnings.

• The first time the cover to the drive unit was cracked, and water had been getting in, causing corrosion. That's why they gave me a new drive unit. Full warranty coverage.
• The second time they diagnosed a female connector that was corroded/splayed open such that even gravity would allow the male pin to come right out. That was my expensive repair as nothing was on warranty there.
• This time they think it's the internals of the battery. They took off the HV pack and pressure tested it. They determined it is leaking (soapy bubbles test), and they believe this is corroding the internal circuit board for the BMS. They ordered a part from California and gave me a loaner for the time being. This is going to be warranty covered, since it's battery related.

Overall I'm lucky that 2 of the 3 issues were under warranty. And they gave me a nice P90D loaner for now, versus my P85 standard.

 

[FrozenCanuck]

Another update: Tesla had ordered a new circuit board for the battery management system (BMS), which is inside the battery. They suspected corrosion on the existing board due to the battery failing the soap bubble leak test.

I guess they opened up my battery and destroyed the seal, and so they put in a request for a brand new HV pack for me. Has to go through usual approval process, but this is like a $20k part and it looks like I’ll get a new battery just before warranty expiry this June

I might be waiting another 4 to 6 weeks. But they gave me that P90D loaner, so I’m pretty happy with what they are doing.

 

[Doanster1]

Anxiety setting in for my P85D that runs out of DU/battery warranty at EOY. Glad to hear 2/3 most expensive items were covered for you!

 

[GazMav]

I've opened the same front cover to get to the BMS board (to replace the contactors) , the sealing from factory is really poor so not surprised one bit.