So this same failure happened to me on my way to Las Vegas this past Friday. I noticed some strange charging behavior before I left my house in Carlsbad in the morning - I had charged it to 90% the night before and then when I woke up Friday morning I set it to top it off for a range charge which was estimated to take 1 hour and 10 minutes. I left about 1 hour 30 minutes later with a full battery (242 RM - 85 kWh battery) but the car didn't think the charge was done. The center screen kept showing the "estimated time to completion" message with no estimated time. I hadn't seen that before on other range charges, but I had a full battery so I didn't think anything of it.
About 2.5 hours later I pull into the Barstow supercharger with about 52 RM left. There's 2 other cars charging but nobody using 1A so I take 1B. Plug in, things are looking normal. I'm about to walk over to the gas station to get a coke when all hell breaks loose on the dash: first charging winds down to zero, then "check charge cable" warning with red light of death on the charge port ring, then "12 V battery low", then "pull over immediately, car may shut down", (even though I wasn't driving), then "systems check failure", then "car may not drive". I try unplugging and replugging the charge cable - no change. I try rebooting both screens, no change. Car refuses to be put into Drive. Oh boy. Call Tesla roadside assistance, they pull the logs, and their next words are "you need to be towed". ARRRRRGGGGHHH. Here I am at the Barstow supercharger on my way to a weekend in Vegas to meet some buddies and I have a dead car. :crying:
This is where things brighten up. Tesla arranges for Enterprise of Barstow to pick me up at the supercharger and arranges for a flatbed to tow the car to the Costa Mesa service center, all within a matter of minutes. Within half an hour I'm headed out of Barstow in a monster GMC Yukon, having left my car at the supercharger. 30 minutes after that I get a call from the towing service saying they have my car and are headed to Costa Mesa. All of this paid for by Tesla. Name a stealership in the entire COUNTRY that would have done that for me.
By Saturday night Costa Mesa had it fixed - the service invoice said "replaced battery coolant heater due to low isolation". Apparently the unit failed just like what happened to the OP of this thread, and now I have a new one. Stayed in Vegas until this morning and drove that behemoth Yukon to Costa Mesa, picked up my car in a matter of minutes, and headed south to Carlsbad. Gotta hand it to Tesla's first class customer service - in almost any other make with a catastrophic failure my weekend in Vegas would likely have been ruined and/or I'd still be trying to figure out how get my car fixed and back. Instead I still got my weekend in Vegas and the fix and the rental cost me nothing but about a 25-minute delay to my arrival time in Vegas, AND I already have my beloved Model S back.
This was my first "must supercharge during the trip" trip even though I've had the car for nearly 2 years. I hope my second one lets me get to my destination in the same car I started with. :scared: