Vehicle lost propulsion and all power mid turn at approximately 45mph. Powe steering and assisted brakes were gone. Conditions were rainy, resulting in single car crash. Car did not restart. No codes present. Occurred again after repairs at 70mph on highway. Codes P0AC4 and P0C0E indicating Drive Motor Power Inverter B. Despite being under warranty, GM cannot repair, and has no replacement parts. GM has ignored messages requesting buyback per federal law.