Isolation Fault

[Dr.K]

P85D 2015. August 20 ? Firmware update scheduled. Temp controlled Garaged Ambient temperature in 70’s. Next morning dash message “ cell low voltage undriveabke call service. “ but charge “49%” then everything black. No app connection either. For several months I have been complaining about low range and told driving style. Frankly it has not changed. I am not a hot Rodder. I am early on drove to and better than spec. Now 2 mi for every 1% of.capacity.

Service report today: “isolation fault” “ “battery coolant heater”

Is not an isolation fault a short?
Is not the heater supposed to be on only when below 70’s.?
Is not the heater on the high voltage circuit?
Does not a short potentially damage the power source? Ie. Battery.
Does not heat fry the battery?
If heater on when in the 70s and 80s is not heat damaging the battery?

I have been getting low range and have been complaining about it. And I have had excess water draining ( from running cooler- can hear the fan making lots of noise so other people note car is noisier) for months but worse in past month.

Told car not ready as they are waiting for “engineer “ to be checking everything a ok. Is that not HQ engineer? Are they trying to determine damage to battery?

Oh my app now connects. They are charging in the station at 2kw. Why this slow? And why does the app still say the car is in my garage? Did it fry something else?

What should I be asking for? Hope there is someway to document good status.

Sounds like this could be like a friend of mines problem with his ICE BMW: his oil service left the filter poorly seated. After the oil leaked out, he had no oil warning but the car OVERHEATED and stoppeD. The service just put the filter straight and they put more oil in and since the engine turned over, he ended up with a kerfufel. HE WAS TOLD ALL THESE ENGINES CONSUME A LOT OF OIL and no damage done. He thought it changed a lot and just quit BMW.

 

[Shadious]

Curious as to what happened to your vehicle? I had a low voltage alert as well and car is waiting at the service center for diagnostics. Could not drive, the main screen and IC also shut down for about 4 hours

 

[Dr.K]

Curious as to what happened to your vehicle? I had a low voltage alert as well and car is waiting at the service center for diagnostics. Could not drive, the main screen and IC also shut down for about 4 hours

the isolation fault was in the heater for the coolant. Ie the coolant is heated to bring battery pack to proper temp. So they replaced it AND the 12v battery. Car works now with better kw/mi numbers.

what they said however was much more interesting and what they did not say and would not say was even more. I have the LG made heater, would love to have an expert open it and see if there was a short that left it effectively on all the the time.thus increasing consumption. What I don’t know is if they did anything else! The kw/mi change was dramatic ~30 + % I noticed this change after driving 1200 miles in sub freezing and near freezing December 4-8 2028 weather with car never in a heated garage. Complained repeatedly to Tesla in Florida when weather was warm and then in north when returned there in summer All complaints dismissed as “driving style” until car quit. My style never changed the car numbers did. The warranty was in effect for the first five months of my complaints. They charged for the repair.
Tesla service is flawed. And their lack of communication is horrible.
I normally would be getting another car right now. In past patterns, my reliable ol car would go into family fleet, not reliable would be traded. Can’t tell what to do with this 3015. I love it, and has not had any significant previous service. But now? Can’t pull the trigger. Between believing 370 vs ~250 range is significant, and suspension supposedly big plus, and MCU and autopilot better and knowing fit and finish big issue and service communication awful. What would you do? Lexus IS not a great car, but it’s service and reliability is great.