Hello, looking for some help here. Wife was driving the car a couple days ago in below 0 F temps when a series of warning indicators flashed. "CRITICAL FAILURE DETECTED, STOP DRIVING WHEN SAFE", "12 Volt Battery Charging System Problem", "Low Battery Charge. Power Reduced" and a red battery icon next to the HV battery gauge. She pulled into a nearby parking lot and the car died. She was able to restart it a little while later, and made it to our driveway before it died again. I have tried the following to resolve the issue with no success: 1. Charged original 12V battery. 2. Replaced 12V battery with a brand-new and freshly charged 12V 500CCA battery. 3. Checked 12V 175A battery fuse in engine compartment (good). 4. Scanned OBD and found zero fault codes. 5. Started car in maintenance mode and measured 11.9V at battery terminals. I continue to get these errors whenever trying to drive the car and a short 1-2 mile drive depletes the new battery to below 12V, after which I have to put it on a tender to bring it up to 12.3V. Wondering if anyone has some insight as to what may be happening here and any other things I can check before dealership appt. Car is 2 months and 1 week past warranty expiration and I'd like to avoid an expensive fix if possible.